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Non-representative sampling of materials, lots and processes intended for NIR analysis is often fraught with hidden contributions to the full Measurement Uncertainty MUtotal = TSE + TAENIR. The Total Sampling Error (TSE) can dominate over the Total Analytical Error TAENIR by factors of 5 to 10 to even 25 times, depending on the degree of material heterogeneity and the specific sampling procedures employed to produce the minuscule aliquot, which is the only material actually analysed. Part 1 presented a brief of all sampling uncertainty elements in the “lot-to-aliquot” pathway, which must be identified and correctly managed (eliminated or reduced maximally), especially the sampling bias, as a prerequisite to achieve fully representative sampling. The key for this is the Theory of Sampling (TOS), which is presented in two parts in a novel compact fashion. Part 2 introduces (i) application of TOS to process sampling, specifically addressing and illustrating how this manifests itself in the realm of PAT, Process Analytical Technology, and (ii) an empirical safeguard facility, termed the Replication Experiment (RE), with which to estimate the effective sampling-plus-analysis uncertainty level (MUtotal) associated with NIR analysis. The RE is a defence against compromising the analytical responsibilities. Ignorance, either caused by lack of awareness or training, or by wilful neglect, of the demand for TSE minimisation, is a breach of due diligence concerning analysis QC/QA. Part 2 ends with a special focus on: “What does all this TOS mean specifically for NIR analysis?”. The answer to this question will perhaps surprise many. There is nothing special that need worrying NIR analysts relative to professionals from all other analytical modalities; all that is needed is embedded in the general TOS framework. Still, this review concludes by answering a set of typical concerns from NIR practitioners.

Non-representative sampling of materials, lots and processes intended for near infrared (NIR) analysis is often contributing hidden additions to the full Measurement Uncertainty (MUtotal = TSE + TAENIR). The Total Sampling Error (TSE) can dominate over the Total Analytical Error (TAENIR) by factors ranging from 5 to 10 to even 25 times, depending on material heterogeneity and the specific sampling procedures employed to produce the minuscule aliquot, which is the only material analysed. This review (Parts 1 and 2), extensively referenced with easily available complementing literature, presents a brief of all sampling uncertainty elements in the “lot-to-aliquot” pathway, which must be identified and correctly managed (eliminated or maximally reduced) in order to achieve, and to be able to document, fully minimised MUtotal. The more irregular and pervasive the heterogeneity, the higher the number of increments needed to reach ‘fit-for-purpose representativity’. A particular focus is necessary regarding the sampling bias, which is fundamentally different from the well-known analytical bias. Whereas the latter can easily be subjected to bias correction, the sampling bias is non-correctable by any posteori means, notably not by chemometrics, nor statistics. Instead, all sampling operations must be designed to exclude the so-called Incorrect Sampling Errors (ISE), which are the hidden bias-generating agents. The key element in this endeavour is representative sampling and sub-sampling before analysis, as laid out by the Theory of Sampling (TOS), which is presented here in a novel compact fashion along with a complement of selected examples and demonstrations. TOS includes a safeguard facility, termed the Replication Experiment (RE), which enables estimation of the total sampling- plus-analysis uncertainty level (MUtotal) associated with NIR analysis (the RE is, for practical and logistical reasons, found in Part 2). Neglecting the TSE effects from the before-analysis domain is lack of due diligence. TOS to the fore!

The fuel quality of hydrogen dispensed from 10 refuelling stations in Europe was assessed. Representative sampling was conducted from the nozzle by use of a sampling adapter allowing to bleed sample gas in parallel while refuelling an FCEV. Samples were split off and distributed to four laboratories for analysis in accordance with ISO 14687 and SAE J2719. The results indicated some inconsistencies between the laboratories but were still conclusive. The fuel quality was generally good. Elevated nitrogen concentrations were detected in two samples but not in violation with the new 300 μmol/mol tolerance limit. Four samples showed water concentrations higher than the 5 μmol/mol tolerance limit estimated by at least one laboratory. The results were ambiguous: none of the four samples showed all laboratories in agreement with the violation. One laboratory reported an elevated oxygen concentration that was not corroborated by the other two laboratories and thus considered an outlier.

Increasing deployment of fuel cell electric vehicles (FCEVs) has led to implementation of hydrogen quality regulations (ISO 14687:2019) to prevent FCEV loss of performance. Hydrogen refuelling stations operators must be able to send representative samples of hydrogen fuel for analysis. Stability of contaminants in sampling vessels needs to be known at ISO 14687:2019 thresholds. A 4-month stability study was carried out on mixtures of ISO 14687 contaminants at amount fractions close to the thresholds in two types of sampling cylinders (SPECTRA-SEAL® and SGS™ aluminium cylinders). SPECTRA-SEAL® cylinder allowed representative sampling of CO, CO2, CH4, C2H6, N2, Ar, He, Cl2CH2, H2O, O2, CH2O2 in hydrogen fuel for 2 months. SGS™ cylinder allowed representative sampling of CO, CO2, CH4, C2H6, N2, Ar, He, Cl2CH2, H2O, O2, H2S for 4 months. Further work is needed to allow representative sampling of ammonia and formaldehyde.

Characterizing and studying oil spills in marine environments for forensic purposes and Natural Resource Damage Assessment often requires timely sampling of multiple, diverse matrices in a range of...

This review summarizes government agency and scientific organization guidance for collecting representative, reliable, and defensible water samples for trace metal analysis, and provides a framewor...

This review summarizes sampling and quality control practices recommended by regulatory agencies and scientific organizations for acquiring reliable, defensible sediment samples in marine environme...

The primary objective of this work is to improve our understanding of the scale effect of the joint shear behavior. Attempts are made to combine different proposed methods with the multiscale joint shear test. First, a new type of rock-like material made from a mixture of raw materials is used to simulate rock joints. Then a new sampling method is used with the progressive coverage statistical method for the representative sampling of actual joints, and an inverse controlling technology is designed with an invented series of multiscale molds for the construction of a similar surface model in series scale (100 mm × 100 mm to 1000 mm × 1000 mm). Finally, the independently developed multiscale direct shear tester is used to measure the shear behavior of joint replicas. The quality of results shows the capacity of this experimental technology in investigating the scale effect of the joint shear behavior.

Age and growth of Nile tilapia, Oreochromis niloticus, from Lake Tana were studied from June 2016 to May 2017. In total, 1 597 otoliths were collected from three representative sampling sites for m...

Knowledge is an important aspect for every person; especially it is very important for physical education teachers, coaches, and athletes. Although the knowledge about nutrition, massage, and physiotherapeutic exercises was investigated in Burundi Country. This study was a descriptive lookup with blended methods. The participants of this lookup were 15 physical education teachers, coaches, and athletes taken by representative sampling. Data evaluation techniques used correlation and linear regression among indicators-variables, and between variables themselves with Software PLS-SEM and SPSS.21. The effects confirmed that there was a low correlation (r: 0.45) between the items-global knowledge, and the negative correlation (r = - 0.068) was found between prices of Gigabyte (GB) and source of learning confirmed that the more the price of gigabyte was expensive, the more the source of information about the learning was not sufficient. The correlation between nutrition and its indicators was not strong, consecutively presented (base: 0.339; components: o.355; knowledge: 0.402). The relation between learning (X1), nutrition (Y1) {Rx1y1: o.421}, and Knowledge (Y3) {Ry1y3} was not strong; the subjects have little knowledge about nutrition. The consecutively correlation of indicators (basics: 0.366; massage course: 0.378; knowledge: 0.441), on massage and physiotherapeutic exercises showed that subjects held little knowledge about the previous courses. Knowledge became strong management tools that help physical education, sport medicine, coaching training managers to decide how to improve peak of performance, to maintain the good quality of athletes and non-athletes: This learn about was the first to apply to evaluate career to the knowledge of physical education teachers, coaches, and athletes.

In this study, the occurrence, spatial distribution, sources, and ecological risks of perfluoroalkyl substances (PFASs) in the surface waters of the Lingang hybrid constructed wetland were systematically investigated. Twenty-three PFASs were analyzed from 7 representative sampling zones. The obtained results indicated that PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFBS, PFOS, and HFPO-DA were frequently detected; and PFBA, PFOA, and PFOS were the dominant PFASs with the relative abundances in ranges of 26.91 to 52.26%, 11.79 to 28.79%, and 0 to 31.98%, respectively. The total concentrations of 8 PFASs (Σ8PFASs) ranged from 25.9 to 56.6 ng/L, and the highest concentration was observed in subsurface flow wetland. Moreover, HFPO-DA with high toxicity was detected in wetlands for the first time. Based on the principal component analysis-multiple linear regression (PCA-MLR) analysis, three sources and their contributions were fluoropolymer processing aids (67.6%), fluororesin coatings and metal plating (17.9%), and food packaging materials and atmospheric precipitation (14.5%), respectively. According to the risk quotients (RQs), the ecological risk of 8 PFASs was low to the aquatic organisms.

The chemical analysis of an urolith is often interpreted as "stone's composition". However, it must be taken into consideration, that in most cases, only a fragment of the stone has been sent to the laboratory. In some recurrent patients, stone compositions either vary considerably between episodes or the analytical result obtained from the stone fragment does not fit with the data of e.g. current 24 h-urinalysis or urinary pH-records. The question arises, whether this outcome may be the result of an improper stone sampling scheme. On a simple layered 2D-stone model composed of two mineral phases it is shown, how the choice of a stone fragment process may influence the result of "stone composition". Depending on the initial position of fragment within the whole stone, the respective calculated analyses can relevantly differ from the whole stone composition as well as strongly between two fragments. Even under the simplified conditions of a 2D-2-component-model "grown" under defined conditions, the differences between the analyses of the different specimens taken from a stone are in part remarkable. The more it can be argued that these differences increase if a real 3D-urolith is investigated. Further sampling biases may evolve and increase the problem of proper sampling:, e.g., if an urolith's more resistant parts remain intact while ESWL or laser-based stone fragmentation ("dusting"), the weak parts became fully disintegrated and removed from the body as fine-grained sludge-the stone's fine fraction is lost although its composition may carry important information on the stone's pathogenesis. Consequently, a "stone analysis" only obtained from the harder remains reveals an incomplete result, a fact that in principle limits its clinical interpretation. Choice of stone fragment is crucial. The extent of the uncertainty of an analysis resulting from potential selection biases should not be underestimated. Thus, sampling should be considered as an important part of the processes of quality assurance and management. Errors made at this early stage of diagnosis finding will affect the analytical result and thus influence the clarification of the underlying pathomechanism. This can lead to an improper metaphylactic strategy potentially causing recurrent stone formation which otherwise would have been prevented. A decision scheme for analysis of urinary stones removed using endoscopic methods is suggested.

Prior Pan-Canadian surveys of Radiation Oncology (RO) residents reveal a decrease in Canadian RO employment opportunities. Canadian RO resident levels increased from 130 in 2003, peaked at 209 in 2009, then decreased to 130 in 2017. Recognizing that RO has entered another period of transition, we re-examined resident motivations and perspectives on the job market and explored well-being and career aspirations among a contemporary cohort of Canadian RO residents. An online survey was distributed to residents at all Canadian RO training programs. Surveys consisted of 75 open-ended, Likert-scale, matrix-style, and multiple-choice questions. Student’s t test compared subgroups, with statistical significance at p ≤ 0.05. Out of 128 eligible residents, 84 completed the survey (66% response rate) with representative sampling from each training year. Demographics reveal 53% male, and 85% Canadian registry–funded. Top training-related stressors were exam performance, job prospects, and physical/psychological demands of residency. Most intend to pursue fellowship post-residency (80%) and practice in Canada (88%). Few believe they can obtain staff positions treating preferred tumor sites (38%) or at preferred geographic locations (28%). Residents view job market being less competitive than 5 years ago (40%) and predict it will be less competitive in 5 years (60%). Canadian RO residents feel adequately trained, and most pursue post-residency fellowships. Current perceptions of the Canadian job market remain guarded, but appear more optimistic about the future. This update provides insights into current RO training and identifies areas that could be addressed by incoming competency-based medical education models for RO.

Background More than 85 patients have received over 100 hand/arm transplants and more than 35 patients have received full or partial face transplants at institutions around the world. Given over two decades of experience in the field and in the light of successful outcomes with up to 17 years follow up time, should we still consider vascularized composite allograft (VCA) as a research/clinical investigation? We present the results of a nationwide electronic survey whose intent was to gather institutional bias with regard to this question. Methods An 11 question survey that was developed by VCA advisory committee of American Society of Transplantation was sent to all identified Internal Review Board chairs or directors in the United States. Results We received a total of 54 responses (25.3%) to the survey. The majority (78%) of responses came from either the chairperson, director, or someone who is administratively responsible for an IRB. Conclusion Though certainly not an exhaustive investigation into each institution's preference, we present a representative sampling. The results of which favor VCA as an accepted clinical procedure given the appropriate setting. Further research is needed to fully ascertain practices at each individual institution.

Purpose: To describe the use of eye care services among adults treated for diabetes from 2008 to 2017 in the French population. Methods: We used a random representative sampling of the French national health insurance database. Participants were adults treated for diabetes. Data regarding visits to ophthalmologists, eye examination procedures, and medical treatments were extracted using reimbursement codes. Cross-sectional analyses of eye care claims were performed each year from 2008 to 2017. Results: Less than 50% of people with diabetes underwent an annual eye examination (2008: 44.7%; 2017: 47.9%), and less than two-thirds underwent a biennial eye examination (2008–2009: 62.6%; 2016–2017: 66.4%). From 2008 to 2017, the yearly use of optical coherence tomography examinations increased steadily and markedly from 2.7% to 16.2%, while the use of fluorescein and indocyanine green angiographies decreased from 2.4% to 0.9%. In the same period, the yearly rate of intravitreal injection increased from 0.3% to 1.5%, and the use of laser photocoagulation decreased progressively from 2008 to 2014 (1.3% vs. 0.7%) but slightly increased from 2015 to 2017 (0.8% vs. 1.0%). Conclusions: Strategies to increase compliance with eye care recommendations are needed to improve early detection and management of diabetic eye complications.

Online social networks (OSNs) have become important platforms for efficiently connecting people and promoting information dissemination, which is of great importance to our social life and society. However, due to privacy concerns, and access limitations, it is difficult to obtain the whole network of OSNs for analysis, so it is critical to have a representative subgraph. Yet due to the same reasons, we are in lack of the original network as the ground truth which poses great challenges on evaluating sampling methods on the performance on unbiasedness, let alone representativeness. Thus uniform sampling (UNI) [Gjoka et al. 2010] was proposed to obtain an unbiased nodal property distribution as of the original network to evaluate the degree of bias of other methods. Yet UNI sampling suffers from its low efficiency, and the representativeness and connectivity of the obtained subgraph, which is formed by the sampled nodes and connections between them, are rarely studied. We propose an adaptive UNI sampling (adpUNI) method to overcome previously mentioned disadvantages of UNI by dividing the userID space into several intervals, whose sampling probability adaptively changes based on its target rate. By adding its neighbors of the targeted node into the sample set (adpUNI+N), we can further improve the performance on sampling efficiency and obtain a more connective and representative subgraph. When applied to Sina Weibo and Twitter, our methods over-perform other classical methods on sampling efficiency, and always have a better performance on connectivity and representativeness than UNI sampling. And we also find that an unbiased sample doesn’t guarantee a more representative subgraph.

Collisions cascades initiated by Ni atoms with energies E = 5, 10, 15, and 20 keV on the surface of nickel at temperatures T = 100, 300, 600, 900, and 1200 K were simulated using the molecular dynamics method. To obtain statistically significant values of the number NFP of Frenkel pairs and fractions of vacancies σvac and interstitial atoms σSIA in clusters of point defects as functions of (E, T), representative sampling of 24 collision cascades was generated for all energies of incident particles and irradiation temperatures. It was found that the values of 〈NFP〉, 〈σvac〉, and 〈σSIA〉 averaged over all surface collision cascades with equal (E, T) parameters exceed the corresponding parameters of collision cascades in bulk nickel modeled under identical conditions. Point defects produced in collision cascades on the surface of nickel tend to form clusters. The primary physical mechanism increasing 〈NFP〉, 〈σvac〉, and 〈σSIA〉 in surface cascades is the spatial separation of vacancies and interstitial atoms induced by the elastic interaction of point defects with the free surface.

Allometric model has been applied worldwide to estimate vegetation biomass for decades. However, this model fails to restrict the accelerating increase of biomass as body size grows. That contradicts to the size-related resource limits and intra-specific competitions. Thus, we tested logistic model with limiting factor of the carrying capacity at the 30-year dominant shrub species in Loess Plateau of China, including Caragana korshinskii (51 branches), Salix psammophila (44 branches) and Vitex negundo (28 branches). Our results indicated that logistic model was statistically effective as allometric model indicated by the adjusted code of determination, p-value, Akaike’s Information Criterion and Root Mean Square Error. It was also of more ecological significances by providing the equilibrium growth rate, equilibrium biomass (the asymptotic biomass as branch grew), and point-of-inflections (thresholds for different trends of biomass increase). That had been double-checked with our measured biomass and the published data in previous studies. The unrepresentative samples with the tendency favoring the small- and middle-sized branches, and the consequently biased tendency and overfitting in models from random quirks of samples, might partly explain the repeated validation of allometric model for estimating biomass in previous studies. In general, logistic model outperformed allometric model to estimate shrub biomass of allometric scaling with body size. An appropriate model for biomass estimation benefited to precisely compute carbon sequencing and to assess climate change impact on ecosystems functioning.

Sampling, sample preparation, and assay protocols aim to achieve an acceptable estimation variance, as expressed by a relatively low nugget variance compared to the sill of the variogram. With gold ore, the typical heterogeneity and low grade generally indicate that a large sample size is required, and the effectiveness of the sampling protocol merits attention. While sampling protocols can be optimised using the Theory of Sampling, this requires determination of the liberation diameter (dℓAu) of gold, which is linked to the size of the gold particles present. In practice, the liberation diameter of gold is often represented by the most influential particle size fraction, which is the coarsest size. It is important to understand the occurrence of gold particle clustering and the proportion of coarse versus fine gold. This paper presents a case study from the former high-grade Crystal Hill mine, Australia. Visible gold-bearing laminated quartz vein (LV) ore was scanned using X-ray computed micro-tomography (XCT). Gold particle size and its distribution in the context of liberation diameter and clustering was investigated. A combined mineralogical and metallurgical test programme identified a liberation diameter value of 850 µm for run of mine (ROM) ore. XCT data were integrated with field observations to define gold particle clusters, which ranged from 3–5 mm equivalent spherical diameter in ROM ore to &gt, 10 mm for very high-grade ore. For ROM ore with clusters of gold particles, a representative sample mass is estimated to be 45 kg. For very-high grade ore, this rises to 500 kg or more. An optimised grade control sampling protocol is recommended based on 11 kg panel samples taken proportionally across 0.7 m of LV, which provides 44 kg across four mine faces. An assay protocol using the PhotonAssay technique is recommended.

Representative sampling forms the foundation for making credible interpretations in any science and nowhere is this more important than in archaeological research regarding past human behaviours. One important avenue for understanding prehistoric human subsistence is through the analysis of food remains which are ubiquitous in coastal midden sites. Due to the density and diversity of midden constituents (such as shell, urchin, crab, etc.) it is a timeconsuming process to identify and quantify all such remains from routine excavations. This is clearly an issue pertinent to coastal Hawaiian archaeological sites. The use of smaller sieve sizes (1.6 mm and 3.2 mm) greatly increases the recovery of small-sized midden remains, making analytical work even more time-consuming. Consequently, the sampling to redundancy method is used to assess the richness of midden retained in the 3.2 mm sieves compared to the 6.4 mm sieves, to determine how much of the 3.2 mm midden is required to obtain a representative sample. The results indicate that 100% of urchin, 25% of shellfish and 100% of crab needs to be sampled. These results clearly demonstrate how to speed up identifying and quantifying midden from Hawaiian archaeological sites, in both research and cultural heritage management settings.

In the chemical analyses of tissues for trace elements, quality control of the tissue sample for its anatomic composition is a critically important step that is frequently overlooked. This is because the analyst often assumes a degree of homogeneity that does not exist. The means of attaining a representative sample vary greatly depending on the organ or tissue involved, and also on the level of resolution chosen, i.e., the size of the sample.

Does any existing single actor have, or could any existing single actor come to have, the authority to geoengineer? In this paper, I will focus on Solar Radiation Management strategies (leaving at ...

Zoonotic transmission of mycobacteria between humans and other animal species is an important aspect of the epidemiology of tuberculosis (TB) in regions of the world where the burden of the disease in humans and other animals is high. This is particularly important in areas in which sociocultural factors increase the possibility for interspecies transmission of different mycobacteria. Carrying out a review of the published literature involving laboratory-confirmed TB cases (by culture) and/or biochemical and molecular identification, we described the presence of Mycobacterium bovis and M. tuberculosis infections in humans and animals from 1975 to 2014. Overall, 1693 isolates of M. tuberculosis complex and other mycobacteria were identified and reported, of which 1131 represented M. tuberculosis, 286 represented M. bovis, 71 represented M. africanum, and 205 represented other mycobacteria. Importantly, 1.3% (15/1131) of the M. tuberculosis isolates reported were identified in cattle, while 8.0% (23/286) of the M. bovis isolates reported were isolated from humans. We suggest that representative sampling of TB cases in both hosts, studied by molecular identification tools, will help significantly in deciphering ongoing transmission between animals and humans in both directions and will enhance TB control in Nigeria.

When developing a process flowsheet, the risks in achieving positive financial outcomes are minimised by ensuring representative metallurgical samples and quality testwork. A case study is presented based on an underground gold operation, where poor metallurgical sampling led to grade and recovery underperformance. Sampling-related issues included: poor liaison between geologists and metallurgists; poor domaining; too few metallurgical samples collected and tested; unrepresentative sample composites and sub-samples; poor laboratory practice; and a lack of documentation and QAQC. These issues led to disruption over four years and are estimated to have cost around US$115M in lost revenue and US$7.5M in corrective expenditure. After an initial characterisation programme, a variability mini-bulk sampling and testwork phase was undertaken. This was followed by a pilot programme, progressing to trial mining and production. The paper emphasises the need for fit for purpose metallurgical sampling and testwork, and the early application of variability sampling.

The metallogeny of tantalum through the geological history has been analyzed. A representative sampling contains mineral deposits of five types: pegmatitic, granitic, alkaligranitic, foidic, and carbonatitic ones. They were formed with a variable intensity during the time range from the Late Mesoarchean to Cenozoic. The most notable resources of tantalum are known in the deposits of the Rodinian cycle, as well as the Pangean and Colombian ones. All these cycles stand out against other ones by a leading role of the deposits associated with alkaline magmas of mantle origin. However, the concentrates of the highest quality to extract tantalum are obtained from the deposits in rare-metal pegmatites and lithium-fluorine granites produced by crustal magmas. Only the pegmatitic deposits are known for the Kenoran cycle in tantalum metallogeny. They contain a maximum amount of such high-quality resources.

ABSTRACT: This study examined the impact of weaning age (4 vs. 6 wk) on rumen morphological and metabolic development in artificially reared lambs. Thirty-two mixed-sex lambs (2 to 5 d old) were randomly allocated to 1 of 2 weaning groups: early weaning (EW; 4 wk) and control (Ctrl; 6 wk). Lambs were individually penned and fed milk replacer (MR; 24% CP and 25% fat, DM basis) at 20% of their corresponding initial BW. Weaning was achieved by gradual reduction of MR allowance over a period of 3 wk using a step-down procedure. Concentrate and meadow hay were offered ad libitum from 1 d of the study until 6 wk, when lambs were transferred to a mixed sward pasture. At week 4, individual DMI were recorded and blood samples collected to measure β-hydroxybutyrate (BHBA) and NEFA. Eight animals per group were euthanized at week 4 and 16 to evaluate short chain fatty acids (SCFA) and histomorphometry of the rumen walls: dorsal (DS), ventral (VS), dorsal blind (DBS), and ventral blind (VBS) sacs. Linear mixed models were used to analyze the effect of weaning treatments at week 4 and 16, and to compare between timepoints and between rumen sites. Dry matter intake and rumen SCFA profiles were similar between groups (P > 0.10) at week 4 and 16. Plasma concentrations of BHBA were greater (P = 0.03) in EW than in Ctrl lambs, while NEFA did not differ (P > 0.10) between groups at week 4. No effect of weaning age on rumen empty weight, and papillae density, length, width, surface area ratio, and muscle layer thickness at any of the 4 rumen sites was found (P > 0.10) at either week 4 or week 16, except for greater (P = 0.02) papillae epithelium thickness in the DBS at week 4 in EW than Ctrl lambs. Papillae morphology and muscular thickness differed across rumen sites at week 4 and week 16 (P < 0.05), except for papillae density and surface area ratio at 4 week (P > 0.10). Rumen papillae length, width, and muscle layer thickness increased while papillae density and surface area ratio decreased (P < 0.05) between 4 and 16 wk. The results of this study indicate that morphological and physiological development of the rumen can be accelerated to support weaning of artificially reared lambs at 4 wk, using a step-down weaning system. Morphological differences between rumen sacs denote that future studies in lambs evaluating the impact of different diets should involve representative sampling across the rumen rather than a single site to more accurately study rumen development and ontogenic changes.

Objective (1) To examine the prevalence of college-aged students on campus who had a history of concussion(s) or traumatic brain injury (TBI) and associated symptoms and (2) to evaluate the rate of campus service utilization among students who had a TBI. Setting A representative sampling, randomly selected campus-wide e-mail was sent out with a Qualtrics online survey. Participants College-aged students (N = 466, n = 429) at a northeastern US university responded and consented to participate in the online survey. Design Descriptive study using an online survey to evaluate the prevalence of TBI and subsequent utility of campus services. Main outcome measures The survey assessed concussion history and the diagnosing clinician, activity in which it occurred, level of consciousness, associated symptoms, and utilization of campus services for academic accommodation. Results Prevalence of concussion/TBI in the study population (51.7%) is notably higher than previous reporting in adult and college populations (∼10%-25%). Campus disability and accommodative services were underutilized (10%-13%) and were accessed more readily by the female population. In addition, there were reportable increases in symptom prevalence and service utilization with a greater number of previous concussions. Conclusions Awareness and utilization of accommodative services, especially with a history of concussions, need to be improved in order to ensure academic and occupational success of students.