Articles from BioMed Central


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  • Vakkamäki, Johanna; Taponen, Suvi; Heikkilä, Anna-Maija; Pyörälä, Satu (BioMed Central, 2017)
    Abstract Background The Finnish dairy herd recording system maintains production and health records of cows and herds. Veterinarians and farmers register veterinary treatments in the system. Milk samples for microbiological analysis are routinely taken from mastitic cows. The laboratory of the largest dairy company in Finland, Valio Ltd., analyzes most samples using real-time PCR. This study addressed pathogen-specific microbiological data and treatment and culling records, in combination with cow and herd characteristics, from the Finnish dairy herd recording system during 2010–2012. Results The data derived from 240,067 quarter milk samples from 93,529 dairy cows with mastitis; 238,235 cows from the same herds served as the control group. No target pathogen DNA was detected in 12% of the samples. In 49% of the positive samples, only one target species and in 19%, two species with one dominant species were present. The most common species in the samples with a single species only were coagulase-negative staphylococci (CNS) (43%), followed by Staphylococcus aureus (21%), Streptococcus uberis (9%), Streptococcus dysgalactiae (8%), Corynebacterium bovis (7%), and Escherichia coli (5%). On average, 36% of the study cows and 6% of the control cows had recorded mastitis treatments during lactation. The corresponding proportions were 16 and 6% at drying-off. For more than 75% of the treatments during lactation, diagnosis was acute clinical mastitis. In the milk samples from cows with a recorded mastitis treatment during lactation, CNS and S. aureus were most common, followed by streptococci. Altogether, 48% of the cows were culled during the study. Mastitis was reported as the most common reason to cull; 49% of study cows and 18% of control cows were culled because of mastitis. Culling was most likely if S. aureus was detected in the milk sample submitted during the culling year. Conclusions The PCR test has proven to be an applicable method also for large-scale use in bacterial diagnostics. In the present study, microbiological diagnosis was unequivocal in the great majority of samples where a single species or two species with one dominating were detected. Coagulase-negative staphylococci and S. aureus were the most common species. S. aureus was also the most common pathogen among the culled cows, which emphasizes the importance of preventive measures.
  • Manyanga, Taru; Tremblay, Mark S; Chaput, Jean-Philippe; Katzmarzyk, Peter T; Fogelholm, Mikael; Hu, Gang; Kuriyan, Rebecca; Kurpad, Anura; Lambert, Estelle V; Maher, Carol; Maia, Jose; Matsudo, Victor; Olds, Timothy; Onywera, Vincent; Sarmiento, Olga L; Standage, Martyn; Tudor-Locke, Catrine; Zhao, Pei; Mikkila, Vera; Broyles, Stephanie T (BioMed Central, 2017)
    Abstract Background Although ‘unhealthy’ diet is a well-known risk factor for non-communicable diseases, its relationship with socio-economic status (SES) has not been fully investigated. Moreover, the available research has largely been conducted in countries at high levels of human development. This is the first study to examine relationships among dietary patterns and SES of children from countries spanning a wide range of human development. Methods This was a multinational cross-sectional study among 9–11 year-old children (n = 6808) from urban/peri-urban sites across 12 countries. Self-reported food frequency questionnaires were used to determine the children’s dietary patterns. Principal Components Analysis was employed to create two component scores representing ‘unhealthy’ and ‘healthy’ dietary patterns. Multilevel models accounting for clustering at the school and site level were used to examine the relationships among dietary patterns and SES. Results The mean age of participants in this study (53.7% girls) was 10.4 years. Largest proportions of total variance in dietary patterns occurred at the individual, site, and school levels (individual, school, site: 62.8%; 10.8%; 26.4% for unhealthy diet pattern (UDP) and 88.9%; 3.7%; 7.4%) for healthy diet pattern (HDP) respectively. There were significant negative ‘unhealthy’ diet-SES gradients in 7 countries and positive ‘healthy’ diet-SES gradients in 5. Within country diet-SES gradients did not significantly differ by HDI. Compared to participants in the highest SES groups, unhealthy diet pattern scores were significantly higher among those in the lowest within-country SES groups in 8 countries: odds ratios for Australia (2.69; 95% CI: 1.33–5.42), Canada (4.09; 95% CI: 2.02–8.27), Finland (2.82; 95% CI: 1.27–6.22), USA (4.31; 95% CI: 2.20–8.45), Portugal (2.09; 95% CI: 1.06–4.11), South Africa (2.77; 95% CI: 1.22–6.28), India (1.88; 95% CI: 1.12–3.15) and Kenya (3.35; 95% CI: 1.91–5.87). Conclusions This study provides evidence of diet-SES gradients across all levels of human development and that lower within-country SES is strongly related to unhealthy dietary patterns. Consistency in within-country diet-SES gradients suggest that interventions and public health strategies aimed at improving dietary patterns among children may be similarly employed globally. However, future studies should seek to replicate these findings in more representative samples extended to more rural representation.
  • Pajunen, Tuulia; Vuori, Erkki; Vincenzi, Frank F; Lillsunde, Pirjo; Smith, Gordon; Lunetta, Philippe (BioMed Central, 2017)
    Abstract Background Alcohol is a well-known risk factor in unintentional drownings. Whereas psychotropic drugs, like alcohol, may cause psychomotor impairment and affect cognition, no detailed studies have focused on their association with drowning. Finland provides extensive post-mortem toxicological data for studies on drowning because of its high medico-legal autopsy rates. Methods Drowning cases, 2000 through 2009, for which post-mortem toxicological analysis was performed, came from the database of the Toxicological Laboratory, Department of Forensic Medicine, University of Helsinki, using the ICD-10 nature-of-injury code T75.1. The data were narrowed to unintentional drowning, using the ICD-10 external-injury codes V90, V92, and W65–74. Each drowning case had its blood alcohol concentration (BAC) and concentrations of other drugs recorded. Evaluation of the contribution of psychotropic drugs to drowning was based on their blood concentration by means of a 6-grade scale. Results Among victims ≥15 years old, unintentional drownings numbered 1697, of which, 303 (17.9%) were boating-related and 1394 (82.1%) non-boating-related. Among these, 65.0% of boating-related and 61.8% of non-boating-related victims were alcohol-positive (=BAC ≥ 50 mg/dL). The male-to-female ratio in alcohol-positive drownings was 7.3. At least one psychotropic drug appeared in 453 (26.7%) drowning cases, with some victims’ bodies showing up to 7 different drugs. Overall 70 different psychotropic drugs were detectable, with 134 (7.9%) cases both alcohol-negative and psychotropic-drug-positive, of these, 59 (3.5%) were graded 4 to 6, indicating a possible to very probable contribution to drowning. Our findings suggest that psychotropic drugs may play a significant role in drowning, in up to 14.5% of cases, independently or in association with alcohol. Conclusions Psychotropic drugs alone or in association with alcohol may be an overlooked risk factor in drowning, due to their effects on psychomotor function and cognition. Future studies should also address other mechanisms—for instance drug-induced long-QT syndrome—by which drugs may contribute to drowning.
  • Hemilä, Harri (BioMed Central, 2017)
    Abstract Background The relative scale has been used for decades in analysing binary data in epidemiology. In contrast, there has been a long tradition of carrying out meta-analyses of continuous outcomes on the absolute, original measurement, scale. The biological rationale for using the relative scale in the analysis of binary outcomes is that it adjusts for baseline variations; however, similar baseline variations can occur in continuous outcomes and relative effect scale may therefore be often useful also for continuous outcomes. The aim of this study was to determine whether the relative scale is more consistent with empirical data on treating the common cold than the absolute scale. Methods Individual patient data was available for 2 randomized trials on zinc lozenges for the treatment of the common cold. Mossad (Ann Intern Med 125:81–8, 1996) found 4.0 days and 43% reduction, and Petrus (Curr Ther Res 59:595–607, 1998) found 1.77 days and 25% reduction, in the duration of colds. In both trials, variance in the placebo group was significantly greater than in the zinc lozenge group. The effect estimates were applied to the common cold distributions of the placebo groups, and the resulting distributions were compared with the actual zinc lozenge group distributions. Results When the absolute effect estimates, 4.0 and 1.77 days, were applied to the placebo group common cold distributions, negative and zero (i.e., impossible) cold durations were predicted, and the high level variance remained. In contrast, when the relative effect estimates, 43 and 25%, were applied, impossible common cold durations were not predicted in the placebo groups, and the cold distributions became similar to those of the zinc lozenge groups. Conclusions For some continuous outcomes, such as the duration of illness and the duration of hospital stay, the relative scale leads to a more informative statistical analysis and more effective communication of the study findings. The transformation of continuous data to the relative scale is simple with a spreadsheet program, after which the relative scale data can be analysed using standard meta-analysis software. The option for the analysis of relative effects of continuous outcomes directly from the original data should be implemented in standard meta-analysis programs.
  • Gurarie, Eliezer; Fleming, Christen H; Fagan, William F.; Laidre, Kristin L.; Hernández-Pliego, Jesús; Ovaskainen, Otso (BioMed Central, 2017)
    Abstract Background Continuous time movement models resolve many of the problems with scaling, sampling, and interpretation that affect discrete movement models. They can, however, be challenging to estimate, have been presented in inconsistent ways, and are not widely used. Methods We review the literature on integrated Ornstein-Uhlenbeck velocity models and propose four fundamental correlated velocity movement models (CVM’s): random, advective, rotational, and rotational-advective. The models are defined in terms of biologically meaningful speeds and time scales of autocorrelation. We summarize several approaches to estimating the models, and apply these tools for the higher order task of behavioral partitioning via change point analysis. Results An array of simulation illustrate the precision and accuracy of the estimation tools. An analysis of a swimming track of a bowhead whale (Balaena mysticetus) illustrates their robustness to irregular and sparse sampling and identifies switches between slower and faster, and directed vs. random movements. An analysis of a short flight of a lesser kestrel (Falco naumanni) identifies exact moments when switches occur between loopy, thermal soaring and directed flapping or gliding flights. Conclusions We provide tools to estimate parameters and perform change point analyses in continuous time movement models as an R package (smoove). These resources, together with the synthesis, should facilitate the wider application and development of correlated velocity models among movement ecologists.
  • Mõttus, Matti; Hernández-Clemente, Rocío; Perheentupa, Viljami; Markiet, Vincent (BioMed Central, 2017)
    Abstract Background The Photochemical Reflectance Index (PRI) calculated from narrow-band spectral reflectance data is a vegetation index which is increasingly used as an indicator of photosynthetic activity. The leaf-level link between the status of photosynthetic apparatus and PRI has been robustly established under controlled light conditions. However, when a whole canopy is measured instantaneously, the PRI signal is heavily modified by vegetation structure and local variations in incident light conditions. To apply PRI for monitoring the photosynthesis of whole canopies under natural conditions, these large-scale measurements need to be validated against simultaneous leaf PRI. Unfortunately, PRI changes dynamically with incident light and has a large natural variation. No generally accepted procedure exists today for determining the PRI of canopy elements in situ. Results We present a successful procedure for in situ measurements of needle PRI. We describe, characterize and test an optical measurement protocol and demonstrate its applicability in field conditions. The measurement apparatus consisted of a light source, needle clip, spectroradiometer and a controlling computer. The light level inside the clip was approximately two-thirds of that on sunlit needle surfaces at midday. During each measurement the needle was inserted into the clip for approximately 5 s. We found no near-instantaneous changes (sub-second scale jumps) in PRI during the measurements. The time constants for PRI variation in light to full shade acclimations were approximately 10 s. The procedure was successfully applied to monitor the greening-up of Scots pine trees. We detected both facultative (diurnal) PRI changes of 0.02 (unitless) and constitutive (seasonal) variations of 0.1. In order to reliably detect the facultative PRI change of 0.02, 20 needles need to be sampled from both sunlit and shaded locations. Conclusions We established a robust procedure for irradiance-dependent leaf (needle) PRI measurements, facilitating empirical scaling of PRI from leaf (needle) to full canopy level and the application of PRI to monitoring the changes in highly structured vegetation. The measured time constants, and facultative and constitutive PRI variations support the use of an artificial light for in situ PRI measurements at leaf (needle) level.
  • Hoffmann, Kristina; De Gelder, Rianne; Hu, Yannan; Bopp, Matthias; Vitrai, Jozsef; Lahelma, Eero; Menvielle, Gwenn; Santana, Paula; Regidor, Enrique; Ekholm, Ola; Mackenbach, Johan P; van Lenthe, Frank J (BioMed Central, 2017)
    Abstract Background The prevalence of obesity increased dramatically in many European countries in the past decades. Whether the increase occurred to the same extent in all socioeconomic groups is less known. We systematically assessed and compared the trends in educational inequalities in obesity in 15 different European countries between 1990 and 2010. Methods Nationally representative survey data from 15 European countries were harmonized and used in a meta-regression of trends in prevalence and educational inequalities in obesity between 1990 and 2010. Educational inequalities were estimated by means of absolute rate differences and relative rate ratios in men and women aged 30–64 years. Results A statistically significant increase in the prevalence of obesity was found for all countries, except for Ireland (among men) and for France, Hungary, Italy and Poland (among women). Meta-regressions showed a statistically significant overall increase in absolute inequalities of 0.11% points [95% CI 0.03, 0.20] per year among men and 0.12% points [95% CI 0.04, 0.20] per year among women. Relative inequalities did not significantly change over time in most countries. A significant reduction of relative inequalities was found among Austrian and Italian women. Conclusion The increase in the overall prevalence aligned with a widening of absolute but not of relative inequalities in obesity in many European countries over the past two decades. Our findings urge for a further understanding of the drivers of the increase in obesity in lower education groups particularly, and an equity perspective in population-based obesity prevention strategies.
  • Girchenko, Polina; Lahti, Jari; Czamara, Darina; Knight, Anna K; Jones, Meaghan J; Suarez, Anna; Hämäläinen, Esa; Kajantie, Eero; Laivuori, Hannele; Villa, Pia M; Reynolds, Rebecca M; Kobor, Michael S; Smith, Alicia K; Binder, Elisabeth B; Räikkönen, Katri (BioMed Central, 2017)
    Abstract Background A recent study has shown that it is possible to accurately estimate gestational age (GA) at birth from the DNA methylation (DNAm) of fetal umbilical cord blood/newborn blood spots. This DNAm GA predictor may provide additional information relevant to developmental stage. In 814 mother-neonate pairs, we evaluated the associations between DNAm GA and a number of maternal and offspring characteristics. These characteristics reflect prenatal environmental adversity and are expected to influence newborn developmental stage. Results DNAm GA acceleration (GAA; i.e., older DNAm GA than chronological GA) of the offspring at birth was associated with maternal age of over 40 years at delivery, pre-eclampsia and fetal demise in a previous pregnancy, maternal pre-eclampsia and treatment with antenatal betamethasone in the index pregnancy, lower neonatal birth size, lower 1-min Apgar score, and female sex. DNAm GA deceleration (GAD; i.e., younger DNAm GA than chronological GA) of the offspring at birth was associated with insulin-treated gestational diabetes mellitus (GDM) in a previous pregnancy and Sjögren’s syndrome. These findings were more accentuated when the DNAm GA calculation was based on the raw difference between DNAm GA and GA than on the residual from the linear regression of DNAm GA on GA. Conclusions Our findings show that variations in the DNAm GA of the offspring at birth are associated with a number of maternal and offspring characteristics known to reflect exposure to prenatal environmental adversity. Future studies should be aimed at determining if this biological variation is predictive of developmental adversity.
  • Bogl, Leonie H; Jelenkovic, Aline; Vuoksimaa, Eero; Ahrenfeldt, Linda; Pietiläinen, Kirsi H; Stazi, Maria A; Fagnani, Corrado; D’Ippolito, Cristina; Hur, Yoon-Mi; Jeong, Hoe-Uk; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Cutler, Tessa L; Kandler, Christian; Jang, Kerry L; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; Derom, Catherine A; Vlietinck, Robert F; Nelson, Tracy L; Whitfield, Keith E; Corley, Robin P; Huibregtse, Brooke M; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Willemsen, Gonneke; Bartels, Meike; van Beijsterveldt, Toos C E M; Pang, Zengchang; Tan, Qihua; Zhang, Dongfeng; Martin, Nicholas G; Medland, Sarah E; Montgomery, Grant W; Hjelmborg, Jacob v B; Rebato, Esther; Swan, Gary E; Krasnow, Ruth; Busjahn, Andreas; Lichtenstein, Paul; Öncel, Sevgi Y; Aliev, Fazil; Baker, Laura A; Tuvblad, Catherine; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Rijsdijk, Fruhling; Magnusson, Patrik K E; Pedersen, Nancy L; Aslan, Anna K D; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Duncan, Glen E; Buchwald, Dedra; Tarnoki, Adam D; Tarnoki, David L; Yokoyama, Yoshie; Hopper, John L; Loos, Ruth J F; Boomsma, Dorret I; Sørensen, Thorkild I A; Silventoinen, Karri; Kaprio, Jaakko (BioMed Central, 2017)
    Abstract Background The comparison of traits in twins from opposite-sex (OS) and same-sex (SS) dizygotic twin pairs is considered a proxy measure of prenatal hormone exposure. To examine possible prenatal hormonal influences on anthropometric traits, we compared mean height, body mass index (BMI), and the prevalence of being overweight or obese between men and women from OS and SS dizygotic twin pairs. Methods The data were derived from the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) database, and included 68,494 SS and 53,808 OS dizygotic twin individuals above the age of 20 years from 31 twin cohorts representing 19 countries. Zygosity was determined by questionnaires or DNA genotyping depending on the study. Multiple regression and logistic regression models adjusted for cohort, age, and birth year with the twin type as a predictor were carried out to compare height and BMI in twins from OS pairs with those from SS pairs and to calculate the adjusted odds ratios and 95% confidence intervals for being overweight or obese. Results OS females were, on average, 0.31 cm (95% confidence interval (CI) 0.20, 0.41) taller than SS females. OS males were also, on average, taller than SS males, but this difference was only 0.14 cm (95% CI 0.02, 0.27). Mean BMI and the prevalence of overweight or obesity did not differ between males and females from SS and OS twin pairs. The statistically significant differences between OS and SS twins for height were small and appeared to reflect our large sample size rather than meaningful differences of public health relevance. Conclusions We found no evidence to support the hypothesis that prenatal hormonal exposure or postnatal socialization (i.e., having grown up with a twin of the opposite sex) has a major impact on height and BMI in adulthood.
  • Suominen, Anna L; Helminen, Sari; Lahti, Satu; Vehkalahti, Miira M; Knuuttila, Matti; Varsio, Sinikka; Nordblad, Anne (BioMed Central, 2017)
    Abstract Background During the 2000s, two major legislative reforms concerning oral health care have been implemented in Finland. One entitled the whole population to subsidized care and the other regulated the timeframes of access to care. Our aim was, in a cross-sectional setting, to assess changes in and determinants of use of oral health care services before the first reform in 2000 and after both reforms in 2011. Methods The data were part of the nationally representative Health 2000 and 2011 Surveys of adults aged ≥ 30 years and were gathered by interviews and questionnaires. The outcome was the use of oral health care services during the previous year. Determinants of use among the dentate were grouped according to Andersen’s model: predisposing (sex, age group), enabling (education, recall, dental fear, habitual use of services, household income, barriers of access to care), and need (perceived need, self-rated oral health, denture status). Chi square tests and logistic regression analyses were used for statistical evaluation. Results No major changes or only a minor increase in overall use of oral health care services was seen between the study years. An exception were those belonging to oldest age group who clearly increased their use of services. Also, a significant increase in visiting a public sector dentist was observed, particularly in the age groups that became entitled to subsidized care in 2000. In the private sector, use of services decreased in younger age groups. Determinants for visiting a dentist, regardless of the service sector, remained relatively stable. Being a regular dental visitor was the most significant determinant for having visited a dentist during the previous year. Enabling factors, both organizational and individual, were emphasized. They seemed to enable service utilization particularly in the private sector. Conclusions Overall changes in the use of oral health care services were relatively small, but in line with the goals set for the reform. Older persons increased use of services in both sectors, implying growing need. Differences between public and private sectors persisted, and recall, costs of care and socioeconomic factors steered choices between the sectors, sustaining inequity in access to care.
  • Hirvonen, Elina A M; Pitkänen, Esa; Hemminki, Kari; Aaltonen, Lauri A; Kilpivaara, Outi (BioMed Central, 2017)
    Abstract Background Polycythemia vera (PV), characterized by massive production of erythrocytes, is one of the myeloproliferative neoplasms. Most patients carry a somatic gain-of-function mutation in JAK2, c.1849G > T (p.Val617Phe), leading to constitutive activation of JAK-STAT signaling pathway. Familial clustering is also observed occasionally, but high-penetrance predisposition genes to PV have remained unidentified. Results We studied the predisposition to PV by exome sequencing (three cases) in a Finnish PV family with four patients. The 12 shared variants (maximum allowed minor allele frequency <0.001 in Finnish population in ExAC database) predicted damaging in silico and absent in an additional control set of over 500 Finns were further validated by Sanger sequencing in a fourth affected family member. Three novel predisposition candidate variants were identified: c.1254C > G (p.Phe418Leu) in ZXDC, c.1931C > G (p.Pro644Arg) in ATN1, and c.701G > A (p.Arg234Gln) in LRRC3. We also observed a rare, predicted benign germline variant c.2912C > G (p.Ala971Gly) in BCORL1 in all four patients. Somatic mutations in BCORL1 have been reported in myeloid malignancies. We further screened the variants in eight PV patients in six other Finnish families, but no other carriers were found. Conclusions Exome sequencing provides a powerful tool for the identification of novel variants, and understanding the familial predisposition of diseases. This is the first report on Finnish familial PV cases, and we identified three novel candidate variants that may predispose to the disease.
  • Tegelberg, Saara; Tomašić, Nikica; Kallijärvi, Jukka; Purhonen, Janne; Elmér, Eskil; Lindberg, Eva; Nord, David G; Soller, Maria; Lesko, Nicole; Wedell, Anna; Bruhn, Helene; Freyer, Christoph; Stranneheim, Henrik; Wibom, Rolf; Nennesmo, Inger; Wredenberg, Anna; Eklund, Erik A; Fellman, Vineta (BioMed Central, 2017)
    Abstract Background Mitochondrial diseases due to defective respiratory chain complex III (CIII) are relatively uncommon. The assembly of the eleven-subunit CIII is completed by the insertion of the Rieske iron-sulfur protein, a process for which BCS1L protein is indispensable. Mutations in the BCS1L gene constitute the most common diagnosed cause of CIII deficiency, and the phenotypic spectrum arising from mutations in this gene is wide. Results A case of CIII deficiency was investigated in depth to assess respiratory chain function and assembly, and brain, skeletal muscle and liver histology. Exome sequencing was performed to search for the causative mutation(s). The patient’s platelets and muscle mitochondria showed respiration defects and defective assembly of CIII was detected in fibroblast mitochondria. The patient was compound heterozygous for two novel mutations in BCS1L, c.306A > T and c.399delA. In the cerebral cortex a specific pattern of astrogliosis and widespread loss of microglia was observed. Further analysis showed loss of Kupffer cells in the liver. These changes were not found in infants suffering from GRACILE syndrome, the most severe BCS1L-related disorder causing early postnatal mortality, but were partially corroborated in a knock-in mouse model of BCS1L deficiency. Conclusions We describe two novel compound heterozygous mutations in BCS1L causing CIII deficiency. The pathogenicity of one of the mutations was unexpected and points to the importance of combining next generation sequencing with a biochemical approach when investigating these patients. We further show novel manifestations in brain, skeletal muscle and liver, including abnormality in specialized resident macrophages (microglia and Kupffer cells). These novel phenotypes forward our understanding of CIII deficiencies caused by BCS1L mutations.
  • Hiitiö, Heidi; Vakkamäki, Johanna; Simojoki, Heli; Autio, Tiina; Junnila, Jouni; Pelkonen, Sinikka; Pyörälä, Satu (BioMed Central, 2017)
    Abstract Background The dairy industry has undergone substantial structural changes as intensive farming has developed during recent decades. Mastitis continues to be the most common production disease of dairy cows. Nationwide surveys of mastitis prevalence are useful in monitoring udder health of dairy herds and to study the impact of structural changes on the dairy industry. This survey on bovine subclinical mastitis was the first based on cow composite milk somatic cell count (SCC) data from the Finnish national health monitoring and milk recording database. A cow with composite milk SCC ≥200,000 cells/ml in at least one of the four test milkings during the year was considered to have subclinical mastitis and a cow with composite milk SCC ≥200,000 cells/ml in three or in all four test milkings during the year to have chronic subclinical mastitis. The aim of the study was to determine the prevalence of subclinical mastitis and chronic subclinical mastitis in Finland in 1991, 2001 and 2010 and to investigate cow and herd factors associated with elevated SCC. Results Prevalence of subclinical mastitis in Finland decreased over recent decades from 22.3% (1991) and 20.1% (2001) to 19.0% (2010). Prevalence of chronic subclinical mastitis was 20.4% in 1991, 15.5% in 2001 and 16.1% in 2010. The most significant cow and herd factors associated with subclinical mastitis or high milk SCC were increasing parity, Holstein breed, free-stalls with an automatic milking system and organic production. Milk SCC were highest from July to September. Main factors associated with chronic mastitis were increasing parity and Holstein breed. Conclusions Prevalence of subclinical mastitis in Finland decreased over recent decades, the greatest change taking place during the first decade of the study. Prevalence of chronic subclinical mastitis significantly decreased from 1991. The most significant factors associated with both types of mastitis were increasing parity and Holstein breed, and for subclinical mastitis also free-stalls with automatic milking. National surveys on mastitis prevalence should be carried out at regular intervals to monitor udder health of dairy cows and to study the impact of the ongoing structural changes in the dairy industry to enable interventions related to udder health to be made when needed.
  • Pawar, Prashant M; Derba-Maceluch, Marta; Chong, Sun-Li; Gandla, Madhavi L; Bashar, Shamrat S; Sparrman, Tobias; Ahvenainen, Patrik; Hedenström, Mattias; Özparpucu, Merve; Rüggeberg, Markus; Serimaa, Ritva; Lawoko, Martin; Tenkanen, Maija; Jönsson, Leif J; Mellerowicz, Ewa J (BioMed Central, 2017)
    Abstract Background Lignocellulose from fast growing hardwood species is a preferred source of polysaccharides for advanced biofuels and “green” chemicals. However, the extensive acetylation of hardwood xylan hinders lignocellulose saccharification by obstructing enzymatic xylan hydrolysis and causing inhibitory acetic acid concentrations during microbial sugar fermentation. To optimize lignocellulose for cost-effective saccharification and biofuel production, an acetyl xylan esterase AnAXE1 from Aspergillus niger was introduced into aspen and targeted to cell walls. Results AnAXE1-expressing plants exhibited reduced xylan acetylation and grew normally. Without pretreatment, their lignocellulose yielded over 25% more glucose per unit mass of wood (dry weight) than wild-type plants. Glucose yields were less improved (+7%) after acid pretreatment, which hydrolyses xylan. The results indicate that AnAXE1 expression also reduced the molecular weight of xylan, and xylan–lignin complexes and/or lignin co-extracted with xylan, increased cellulose crystallinity, altered the lignin composition, reducing its syringyl to guaiacyl ratio, and increased lignin solubility in dioxane and hot water. Lignin-associated carbohydrates became enriched in xylose residues, indicating a higher content of xylo-oligosaccharides. Conclusions This work revealed several changes in plant cell walls caused by deacetylation of xylan. We propose that deacetylated xylan is partially hydrolyzed in the cell walls, liberating xylo-oligosaccharides and their associated lignin oligomers from the cell wall network. Deacetylating xylan thus not only increases its susceptibility to hydrolytic enzymes during saccharification but also changes the cell wall architecture, increasing the extractability of lignin and xylan and facilitating saccharification.
  • Mikkonen, Susanna; Pylväs, Laura; Rintala, Heta; Nokelainen, Petri; Postareff, Liisa (Springer International Publishing, 2017)
    Abstract This review provides an overview of the empirical research concerning guidance in the context of vocational education and training (VET). The study examines practices, providers and supporting and hindering factors related to guidance and learning at the workplace. After the inclusion/exclusion process, the final number of research articles included in this review is 18. Results show strong evidence for the collective nature of workplace guidance, with the entire work community providing learners with guidance and assistance. Guidance provided to VET students at workplaces seems to relate strongly to the activities of the members of communities of practice. Guidance provided by the members of communities of practice opens up opportunities for learners to participate in collective practices by gradually assuming more responsibility and more demanding tasks as their skills develop. The learner’s self-regulative skills, such as responsibility and the ability to take the initiative and to actively seek guidance, affect how guidance is afforded to him/her in the work community during training. Furthermore, these skills may also determine the learner’s prospects for developing expertise in future workplaces.