Effects of parity, seasonal heat stress, and colostrum collection time postpartum on colostrum quality of Holstein cattle in an arid region.

The aim of this study was to determine effects of parity (primiparous vs. multiparous), seasonal heat stress at calving (summer vs. winter), and time postpartum on some parameters associated with colostrum quality in Holstein cows reared in the Sonoran Desert ecosystem. Forty-seven cows (11 primiparous and 36 multiparous) expected to calve during summer, and 46 cows during winter (14 primiparous and 32 multiparous) were randomly selected. Management and feeding before and after parturition were similar for cows in both seasons. After parturition, colostrum from all cows was evaluated for volume, weight, temperature, density, and content of fat, protein, solids non-fat (SNF), and immunoglobulins (IGG). Data were analyzed with a model that included effects of parity status, calving season, and time postpartum, as well as all interactions. Colostrum produced in summer was warmer (P < 0.01) by almost 6 °C than winter colostrum, while colostrum from multiparous was warmer (P = 0.02) by 1.2 °C than that produced by primiparous cows. Colostrum volume and weight were not impacted by parity, calving season or time postpartum. Density, protein, and SNF content in colostrum were higher (P < 0.01) in multiparous vs. primiparous cows, as well as at parturition (0 h postpartum) than at 12 h postpartum (P < 0.01). At calving (0 h), spring colostrum had higher fat content (P < 0.01) and lower (P < 0.01) IGG concentration than that collected in summer, and no difference (P > 0.05) between seasons was observed for these components at 12 h postpartum. Multiparous cows produced colostrum with higher (P < 0.01) IGG concentrations than primiparous cows. In conclusion, only 0-h colostrum and that from multiparous cows was categorized as "Excellent," meanwhile the colostrum produced under summer heat stress was characterized as "Good" with reduced fat content. While the lacteal secretion collected at 12 post-partum still classified as colostrum, substantially lower contents of IGG, protein, fat, and SNF decreased its classification to "Poor" from the classification of "Excellent" at 0 h postpartum.

First report of Metathelazia capsulata in red foxes (Vulpes vulpes) in Europe and new contributions to its identification.

Metathelazia capsulata is a lungworm that inhabit in the bronchi and bronchioles from mammal carnivore species, which life cycle is unknown. M. capsulata-like spirurid nematodes were isolated at necropsy from the respiratory tract of red foxes (Vulpes vulpes) from the Region of Murcia (SE Spain). The main objective of this study was to describe in detail the morphometric features of these nematodes, as well as to report some molecular markers. The principal morphometric difference compared to previous M. capsulata descriptions was the shorter total length for both males and females (6.6 mm and 7.4 mm, respectively). In addition, the mean values of buccal cavity depth and distance between the excretory pore and the anterior end of the nematode were also lower than those previously reported. On the other hand, sequence data of the mitochondrial (COI) and nuclear (rDNA) genes of M. capsulata were described, being the first time that molecular markers are reported for the genus Metathelazia and also for the entire family Pneumospiruridae. Based on data available from GenBank, these results indicate that M. capsulata sequences are closely related to the family Rhabdochonidae, which is assumed to belong to superfamily Thelazioidea, a superfamily including the family Pneumospiruridae, but also suggest the distant relations with the family Thelaziidae. This is the first time that M. capsulata is reported in red fox from Europe. This study provides valuable information for future phylogenetic studies on Metathelazia spp. nematodes and, in general, on species of the family Pneumospiruridae.

Incidence of SARS-CoV-2 infection among previously infected or vaccinated employees.

INTRODUCTION: We aimed to determine the incidence of SARS-CoV-2 infection among individuals with a previous SARS-CoV-2 infection versus vaccinated individuals. METHODS: In March 2020, a SARS-CoV-2 testing company began routinely screening its workforce for SARS-CoV-2 with a PCR test. On December 15, 2020, vaccination with either the BNT162b2 or mRNA-1273 vaccines became available. Routine screening has continued through July 2021. We compared the incidence of SARS-CoV-2 infection between people who were SARS-CoV-2 naïve and unvaccinated, people with prior COVID-19 without vaccination, and people vaccinated without prior COVID-19. Incidence in 100 person-years with 95% confidence intervals (95% CIs) was calculated with the Poisson Exact equation. The incidence rate ratio (IRR), the ratio of confirmed COVID-19 cases per 100 person-years of follow-up with 95% CIs, was used as a measure of association between groups. Analyses were performed on StataSE. RESULTS: The median age of employees was 29.0 years (interquartile range: 23.6, 39.9). During the observation period, 258 SARS-CoV-2 incident infections were identified. The naïve, unvaccinated group had a SARS-CoV-2 incidence of 25.9 per 100 person-years (95% CI: 22.8-29.3). The previously infected, unvaccinated group had an incidence of 0 per 100 person-years (95% CI: 0-5.0). The vaccinated group had an incidence of 1.6 per 100 person-years (95% CI: 0.04-4.2). CONCLUSION: We found a strong association between prior SARS-CoV-2 infection and/or vaccination for SARS-CoV-2 with either the BNT162b2 or mRNA-1273 vaccines and the reduced incidence of SARS-CoV-2 infection when compared with those naïve and/or unvaccinated to SARS-CoV-2.

Effects of a lower extremity exercise program on gait biomechanics and clinical outcomes in children and adolescents with obesity: A randomized controlled trial.

BACKGROUND: Research highlights the detrimental effects of obesity on gait biomechanics and the accompanied risk of lower-extremity skeletal malalignments, increased joint stress, pain and discomfort. Individuals with obesity typically show increased knee valgus angles combined with an increased step width. Accompanying muscular dysfunctions impede their ability to compensate for these alterations, especially in the frontal plane. To date, no studies are available, which evaluated the potential effects of an exercise program (EP) in reducing these unfavorable biomechanical changes. RESEARCH QUESTIONS: Is a 12-week EP, which includes hip abductor and knee extensor strength exercises and fosters dynamic knee alignment, effective in positively altering gait biomechanics in children and adolescents with obesity? METHODS: This study was a randomized controlled trial having children and adolescents with obesity assigned to an EP (n = 19) or control (n = 16) group. Pain, self-rated knee function, muscle strength and 3D gait analysis during walking and stair climbing were evaluated. RESULTS: Results indicate that the EP was able to increase muscular strength especially in the hip abductors. In addition, children from the EP group walked with less maximum hip adduction and reduced pelvic drop during weight acceptance at follow-up. No changes were present in self-rated knee function, pain or discomfort. SIGNIFICANCE: Even though effects were small, results indicate that an EP is an effective short-term possibility to counteract the progressive development of biomechanical malalignments of the lower extremity. Clinical parameters indicated that the program was feasible. Nonetheless, low adherence highlights the need to develop more attractive programs. CLINICAL TRIALS REG. NO: clinicaltrials.gov (NCT02545764).

Reliability of joint kinematic calculations based on direct kinematic and inverse kinematic models in obese children.

BACKGROUND: In recent years, the reliability of inverse (IK) and direct kinematic (DK) models in gait analysis have been assessed intensively, but mainly for lean populations. However, obesity is a growing issue. So far, the sparse results available for the reliability of clinical gait analysis in obese populations are limited to direct kinematic models. Reliability error-margins for inverse kinematic models in obese populations have not been reported yet. RESEARCH QUESTIONS: Is there a difference in the reliability of IK models compared with a DK model in obese children? Are there any differences in the joint kinematic output between IK and DK models? METHODS: A test-retest study was conducted using three-dimensional gait analysis data from two obese female and eight obese male participants from an earlier study. Data were analyzed using a DK model and two OpenSim-based IK models. Test-retest reliability was compared by calculating the Standard Error of Measurement (SEM) along with similar absolute reliability measures. A Friedman Test was used to assess whether there were any significant differences in the reliability between the models. Kinematic output of the models was compared by using Statistical Parametric Mapping (SPM). RESULTS: No significant differences were found in the reliability between the DK and IK models. The SPM analysis indicated several significant differences between both IK models and the DK approach. Most of these differences were continuous offsets. SIGNIFICANCE: Reliability values showed clinically acceptable error-margins and were comparable between all models. Therefore, our results support the careful use of IK models in overweight or obese populations, e.g. for musculoskeletal modelling studies. The inconsistent kinematic output can mainly be explained by different model conventions and anatomical segment coordinate frame definitions.

Evaluation of oxidative stress via total antioxidant status, sialic acid, malondialdehyde and RT-PCR findings in sheep affected with bluetongue.

INTRODUCTION: Bluetongue (BT) is a non-contagious infectious disease of ruminants. The disease agent bluetongue virus (BTV) is classified in the Reoviridae family Orbivirus. AIMS AND OBJECTIVES: The aim of this study was to determine serum malondialdehyde (MDA), total antioxidative stres (TAS), total sialic acid (TSA), ceruloplasmin, triglyceride, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), cholesterol, creatinine, albumin, and total protein levels in sheep with and without bluetongue (BT). MATERIALS AND METHODS: The study included 13 Sakiz crossbreed sheep, aged 1-4 years and usually in the last stage of pregnancy, as the BT group and a control group consisting of 10 healthy sheep. All sheep were clinically examined before collecting blood samples. Serum ALT, AST, cholesterol, triglyceride, albumin, GGT, total protein, creatinine and TAS levels were measured using commercially available kits as per manufacturer's recommendations using a Biochemistry Auto Analyzer (Sinnowa D280, China). Serum lipid peroxidation was estimated through a previously described method in which MDA reacts with thiobarbituric acid (TBA) to form a coloured complex at a maximum absorbance of 535 nm. The TSA value was measured at 549 nm using the method described by Warren (1959): sialic acid was oxidised to formyl-pyruvic acid, which reacts with TBA to form a pink product. The ceruloplasmin concentration was measured according to Sunderman and Nomoto (1970): ceruloplasmin and p-phenylenediamine formed a coloured oxidation product that was proportional to the concentration of serum ceruloplasmin. Real time RT-PCR and conventional RT-PCR were performed as described by Shaw and others (2007). RESULTS: Biochemistry analysis of serum showed that in the BT group, TSA, MDA, triglyceride and ALT and AST were higher and that ceruloplasmin and TAS were lower than in the control group. Serum albumin, cholesterol, creatinine, total protein and GGT did not differ significantly between the two groups. CONCLUSIONS: Serum triglyceride, ceruloplasmin, TSA, MDA and TAS concentrations may prove beneficial to the diagnosis, prognosis and biochemical analysis of BT.

Effect of defensive pressure on movement behaviour during an under-18 basketball game.

The aim of this study was to examine the effect of defensive pressure on movement behaviour during an under-18 basketball game. 20 international male players (age: M=16.05, SD=2.09 years old; weekly practice: M=10.9, SD=1.94 h; playing experience: M=7.1, SD=1.1 years) played two 10-min basketball quarters, using man-to-man »-court for the first 4 min (F»), man-to-man full court defence for the next 3 min (FULL), and man-to-man »-court defence for the last 3 min (S»). The positional data were captured by the Ubisense Real Time Location System and analysed with non-linear signal processing methods (approximate entropy) and repeated measures ANOVA. There were differences in the regularity values between F» and FULL in distance to the basket and to the opponents' basket. A stronger in-phase attraction in both lateral and longitudinal directions was identified; however, the centroids (i. e., the mean position from all team players) were closer and revealed higher values of irregularity in lateral displacements for all defensive systems. The individual speed displacements became more coordinated with teammates, particularly in the offensive court. Overall, this study provided evidence on how changing the level of defensive pressure promotes different collective behaviours.

Genotypes of Streptococcus mutans in saliva versus dental plaque.

OBJECTIVE: The aim of this study was to investigate whether genotypes of Streptococcus mutans strain can be detected as effectively in saliva samples as in plaque samples from buccal surfaces and occlusal surface fissures of permanent first molars. DESIGN: The study included 20 school children aged 6-7 years who were positive for mutans streptococci. Samples of stimulated saliva and of dental plaque on buccal surfaces and occlusal surface fissures of permanent first molars were collected. Samples were cultivated in MSB agar. Up to nine isolates compatible with mutans streptococci were obtained and identified by means of biochemical tests. All isolates identified as S. mutans were genotyped by arbitrarily primed polymerase chain reaction. RESULTS: A total of 28 genotypes of S. mutans were isolated: 23 in saliva samples, 23 in buccal surface plaque samples, and 16 in plaque samples from occlusal surface fissures. CONCLUSIONS: Although, saliva sampling did not reveal all genotypes isolated, it was equally as effective as plaque sampling from the buccal surfaces of permanent first molars, and more effective than plaque sampling from fissures on their occlusal surfaces.

Mutans streptococci and lactobacilli in saliva after the application of fissure sealants.

Because dental fissures may serve as reservoirs for mutans streptococci, preventive measures should be taken to control microbial concentrations at these sites. This study estimated the influence that sealing permanent first molars would have on the levels of mutans streptococci and lactobacilli in saliva of healthy seven-year-old schoolchildren. Permanent first molars were sealed in 31 children without caries (NC group) and in 32 children with caries (C group). None of the children had caries in their permanent first molars. Conventional methods were used to count mutans streptococci and lactobacilli in saliva before applying the sealant and again at 4 and 12 weeks after application. Baseline counts of lactobacilli and mutans streptococci were significantly higher in the C group. A significant reduction in mutans streptococci was observed in the NC group at 4 and 12 weeks. It was concluded that fissure sealants in permanent first molars can help reduce salivary levels of mutans streptococci in children without caries.

Performance of AlGaN/GaN high electron mobility transistors at nanoscale gate lengths.

The DC and RF performance of AlGaN/GaN high electron mobility transistors with nanoscale gate lengths is presented. The layer structures were grown by either metal organic chemical vapor deposition or rf plasma-assisted molecular beam epitaxy. Excellent scaling properties were observed as a function of both gate length and width and confirm that these devices are well suited to both high speed switching and power microwave applications.

Crystal structure of Mycobacterium tuberculosis 7,8-dihydropteroate synthase in complex with pterin monophosphate: new insight into the enzymatic mechanism and sulfa-drug action.

The enzyme 7,8-dihydropteroate synthase (DHPS) catalyzes the condensation of para-aminobenzoic acid (pABA) with 6-hydroxymethyl-7, 8-dihydropterin-pyrophosphate to form 7,8-dihydropteroate and pyrophosphate. DHPS is essential for the de novo synthesis of folate in prokaryotes, lower eukaryotes, and in plants, but is absent in mammals. Inhibition of this enzyme's activity by sulfonamide and sulfone drugs depletes the folate pool, resulting in growth inhibition and cell death. Here, we report the 1.7 A resolution crystal structure of the binary complex of 6-hydroxymethylpterin monophosphate (PtP) with DHPS from Mycobacterium tuberculosis (Mtb), a pathogen responsible for the death of millions of human beings each year. Comparison to other DHPS structures reveals that the M. tuberculosis DHPS structure is in a unique conformation in which loop 1 closes over the active site. The Mtb DHPS structure hints at a mechanism in which both loops 1 and 2 play important roles in catalysis by shielding the active site from bulk solvent and allowing pyrophosphoryl transfer to occur. A binding mode for pABA, sulfonamides and sulfones is suggested based on: (i) the new conformation of the closed loop 1; (ii) the distribution of dapsone and sulfonamide resistance mutations; (iii) the observed direction of the bond between the 6-methyl carbon atom and the bridging oxygen atom to the alpha-phosphate group in the Mtb DHPS:PtP binary complex; and (iv) the conformation of loop 2 in the Escherichia coli DHPS structure. Finally, the Mtb DHPS structure reveals a highly conserved pterin binding pocket that may be exploited for the design of novel antimycobacterial agents.

Overcoming codon bias: a method for high-level overexpression of Plasmodium and other AT-rich parasite genes in Escherichia coli.

Parasite genes often use codons which are rarely used in the highly expressed genes of Escherichia coli, possibly resulting in translational stalling and lower yields of recombinant protein. We have constructed the "RIG" plasmid to overcome the potential codon-bias problem seen in Plasmodium genes. RIG contains the genes that encode three tRNAs (Arg, Ile, Gly), which recognise rare codons found in parasite genes. When co-transformed into E. coli along with expression plasmids containing parasite genes, RIG can greatly increase levels of overexpressed protein. Codon frequency analysis suggests that RIG may be applied to a variety of protozoan and helminth genes.

A comparison of methods for analyzing drop jump performance.

PURPOSE: Drop jumping is a popular form of plyometric training. Different techniques are applied to determine parameter values quantifying drop jumps, such as the jump height or the durations of the phases of downward and upward movements of the center of mass (CM) during foot contact with the ground after dropping. The flight-time method estimates the jump height from the time between the instant of leaving the ground and the instant of landing. In video-based methods, markers are placed on the skin of the subject to define the positions of the body segments. The time-dependent positions of the CM and parameter values are then calculated utilizing models of the human body. If the vertical velocity of the CM can be estimated at one instant, the parameter values can be calculated from the vertical ground reaction forces. METHODS: The purpose of this study was to find out which technique yields the lowest errors compared with the results obtained by the double force plate technique. In this investigation, two force plates were used, one located under the drop platform. Twenty-five drop jumps were analyzed with eight different methods. There were large differences between the reference method and other methods. Using the height of the drop platform (0.39 m) to estimate the velocity at the end of the free fall, in conjunction with data from one force plate, resulted in a mean difference of 4.2% (SD: 9.6%) in the calculated jump height. Using video information to estimate the time that the velocity of the CM fell to zero after the drop phase, in conjunction with data from one force plate, resulted in differences in the jump height of up to 17%. RESULTS: Differences between the reference method and video based methods were comparatively small (mean value of differences in jump height: -0.007 m, SD: 0.013 m for the best of these methods) but not negligible. CONCLUSIONS: Nevertheless, video based methods turned out to be the most promising alternative to the reference method to determine accurate variables concerning drop jump performance.

Application of computer animation techniques for presenting biomechanical research results.

Computer animation is becoming a widely accepted method for presenting results of biomechanical analyses and simulations. After summarizing the main aspects of three-dimensional and video overlaid animation, two applications of these techniques are presented. A parameterized graphical model of the tennis racket has been developed, which can be used for visualizing the simulated ball-racket impact phase. In the second example, high-speed video sequences of recorded drop jumps are overlaid with graphical elements to compare methods for determining the jumping height and related parameters. These graphical elements represent quantities, which are calculated applying the different methods. Differences can vividly be demonstrated.

Spatial reconstruction of marker trajectories from high-speed video image sequences.

A novel method is presented for the spatial reconstruction of marker trajectories, which describe the motion of articulating segments of the human or animal body or of a technical construction. In human motion analysis, such markers may be attached to landmark points defining the configuration of the subject. A high-speed video-recording system comprising two cameras is used for motion data acquisition. The particular images are composed of the synchronous recordings of both cameras; the resolution of one image is 239 x 192 pixels, which is comparatively low. To obtain high precision, a new centre estimation method has been developed to calculate the image coordinates of the centres of the recorded spherical markers to subpixel precision. Image coordinates of the centres in subsequent frames are obtained by first applying a tracing algorithm, which calculates the position of a marker to pixel precision, and then using the new centre estimation method. The reconstruction of the spatial coordinates from the image coordinates is based on a three-dimensional photogrammetric calibration and results in deviations of about 0.1%. The instantaneous acceleration of a falling ball has been calculated. The average deviation from the gravitational constant was comparatively small. From the accuracy of the results, it can be concluded that the novel method is applicable in connection with the high-speed video-recording system presently used. Moreover, the techniques are suitable for reconstructing three-dimensional marker trajectories from any low-resolution video image sequences recorded simultaneous with at least two cameras.

Precise determination of anthropometric dimensions by means of image processing methods for estimating human body segment parameter values.

A method has been developed for the precise determination of anthropometric dimensions from the video images of four different body configurations. High precision is achieved by incorporating techniques for finding the location of object boundaries with sub-pixel accuracy, the implementation of calibration algorithms, and by taking into account the varying distances of the body segments from the recording camera. The system allows automatic segment boundary identification from the video image, if the boundaries are marked on the subject by black ribbons. In connection with the mathematical finite-mass-element segment model of Hatze, body segment parameters (volumes, masses, the three principal moments of inertia, the three local coordinates of the segmental mass centers etc.) can be computed by using the anthropometric data determined videometrically as input data. Compared to other, recently published video-based systems for the estimation of the inertial properties of body segments, the present algorithms reduce errors originating from optical distortions, inaccurate edge-detection procedures, and user-specified upper and lower segment boundaries or threshold levels for the edge-detection. The video-based estimation of human body segment parameters is especially useful in situations where ease of application and rapid availability of comparatively precise parameter values are of importance.