513 research outputs found
Dry Forage Transportation Solution
• The ISU Beef Nutrition Farm has no way to transport multiple large round hay bales from the field to the storage area on the farmyard in one trip
• This results in many trips from the yard to the field picking up one bale at a tim
Geographic variation in host selection in the spider wasps \u3ci\u3eEntypus unifasciatus\u3c/i\u3e (Say) and \u3ci\u3eTachypompilus ferrugineus\u3c/i\u3e (Say) (Hymenoptera: Pompilidae), II
This paper is the sequel to a 20 year-long (2002–2021) study of geographic variation in host selection in the common American spider wasps (Hymenoptera: Pompilidae) Entypus unifasciatus (Say) (Pepsini) and Tachypompilus ferrugineus (Say) (Pompilini) (rusty spider wasp). Geography and host spider family are strongly linked in both species when 3387 host spider locality records from the years 1918–2021 are mapped. Entypus unifasciatus lycosid host records are plentiful from 43–44° N in the United States and southern Ontario to northern Mexico. Tachypompilus ferrugineus lycosid host records are abundant from southern Ontario and New England southward to Mexico east of the Rocky Mountains. The vast majority (~80%) of E. unifasciatus and T. ferrugineus pisaurid host records are from the southeastern United States. Trechaleid host records for E. unifasciatus and T. ferrugineus are predominant in southern Mexico and Central America, while ctenid host records for these spider wasps are prevalent in Central America and, especially, South America. All E. unifasciatus sparassid host records are from extreme southwestern United States and northern Mexico, whereas T. ferrugineus sparassid host records are scattered from Texas, Florida and Hispaniola/Puerto Rico southward to Panama and Brazil. Based on this study Lycosidae is the predominant host spider family in the Americas for E. unifasciatus (83.1%) and T. ferrugineus (64.0%) followed by Pisauridae (4.9%, 24.8%), Trechaleidae (4.2%, 6.0%), Ctenidae (4.3%, 2.7%), and Sparassidae (3.1%, 1.6%). Lycosidae and Pisauridae are overrepresented in this study as most host records (88.1%) are from the United States and Ontario, Canada where such species are abundant. Trechaleidae and Ctenidae are grossly underrepresented as host records from Mexico, Central America and South America are scarce (11.9%). Zoropsidae/Miturgidae 2 · March 31, 2022 Kurczewski et al. and Zoropsidae/Agelenidae/Selenopidae are atypical host spider families for E. unifasciatus (0.2%, 0.2%) and T. ferrugineus (0.7%, 0.2%, \u3c0.1%), respectively. Rabidosa rabida (Walckenaer) (Lycosidae) (rabid wolf spider) is the predominant host spider species for both E. unifasciatus (47.7%) and T. ferrugineus (48.0%) based mainly on United States host records
Structure and Magnetization of Two-Dimensional Vortex Arrays in the Presence of Periodic Pinning
Ground-state properties of a two-dimensional system of superconducting
vortices in the presence of a periodic array of strong pinning centers are
studied analytically and numerically. The ground states of the vortex system at
different filling ratios are found using a simple geometric argument under the
assumption that the penetration depth is much smaller than the spacing of the
pin lattice. The results of this calculation are confirmed by numerical studies
in which simulated annealing is used to locate the ground states of the vortex
system. The zero-temperature equilibrium magnetization as a function of the
applied field is obtained by numerically calculating the energy of the ground
state for a large number of closely spaced filling ratios. The results show
interesting commensurability effects such as plateaus in the B-H diagram at
simple fractional filling ratios.Comment: 12 pages, 19 figures, submitted for publicatio
The speciation and genotyping of Cronobacter isolates from hospitalised patients
The World Health Organization (WHO) has recognised all Cronobacter species as human pathogens. Among premature neonates and immunocompromised infants, these infections can be life-threatening, with clinical presentations of septicaemia, meningitis and necrotising enterocolitis. The neurological sequelae can be permanent and the mortality rate as high as 40 – 80 %. Despite the highlighted issues of neonatal infections, the majority of Cronobacter infections are in the elderly population suffering from serious underlying disease or malignancy and include wound and urinary tract infections, osteomyelitis, bacteraemia and septicaemia. However, no age profiling studies have speciated or genotyped the Cronobacter isolates. A clinical collection of 51 Cronobacter strains from two hospitals were speciated and genotyped using 7-loci multilocus sequence typing (MLST), rpoB gene sequence analysis, O-antigen typing and pulsed- field gel electrophoresis (PFGE). The isolates were predominated by C. sakazakii sequence type 4 (63 %, 32/51) and C. malonaticus sequence type 7 (33 %, 17/51). These had been isolated from throat and sputum samples of all age groups, as well as recal and faecal swabs. There was no apparent relatedness between the age of the patient and the Cronobacter species isolated. Despite the high clonality of Cronobacter , PFGE profiles differentiated strains across the sequence types into 15 pulsotypes. There was almost complete agreement between O-antigen typing and rpoB gene sequence analysis and MLST profiling. This study shows the value of applying MLST to bacterial population studies with strains from two patient cohorts, combined with PFGE for further discrimination of strains
Cronobacter spp. as emerging causes of healthcare-associated infection
Background: Until recently, members of the Cronobacter genus (formerly known as Enterobacter sakazakii) were a relatively unknown cause of nosocomial infections. However, their association with infant infections, particularly through the consumption of contaminated reconstituted infant formula in neonatal intensive care units, has resulted in international efforts to improve neonatal health care. Aim: To investigate current understanding of this emergent group of bacterial pathogens and the steps taken to reduce neonatal infection. Methods: A literature review was undertaken to determine current knowledge of the Cronobacter genus with respect to recent taxonomic revisions, sources and clinical relevance. Findings: The majority of severe neonatal meningitis infections are associated with one of the 10 Cronobacter spp., the clonal complex known as C. sakazakii sequence type 4. International efforts by the Food and Agriculture Organization–World Health Organization (WHO) to reduce the risk of neonatal infection by this organism have resulted in improved microbiological safety of powdered infant formula (PIF), but revised guidelines for feeding practices have been problematic. In addition, the majority of infections occur in the adult population and the sources are unknown. Conclusion: International improvements in the microbiological safety of PIF and advice on feeding practices have focused on improving neonatal health care following the heightened awareness of Cronobacter infections in this particular age group. These measures are also likely to reduce neonatal exposure to other opportunistic bacterial pathogens, but a number of unresolved issues remain with respect to the practicalities of feeding premature neonates safely while following WHO advice
Ultra-Fast Activity and Intraday Market Quality
This paper studies the intraday relationship between ultra-fast machine-driven activity (UFA) and market quality in automated equity markets. We find that higher UFA is associated with lower intraday market quality (greater quoted and effective spreads and lower depth). This effect is economically significant, and robust to different specifications, endogeneity tests, and alternative measures of UFA. Our results hold after controlling for volatility, periods of unusually high UFA (a proxy for quote stuffing), and periods where UFA is primarily driven by fleeting orders inside the spread (a proxy for spoofing and competition between liquidity providers)
On thermodynamic modeling and the role of the second law of thermodynamics in geophysics
The article contains a brief review of elements of thermodynamic modeling in theoretical geophysics. We motivate the existence of the second law of thermodynamics in macroscopic theoretical physics and demonstrate its evaluation. In particular we show its consequences in the construction of constitutive laws for a two-component poroelastic medium. This construction is also related to microstructural properties verified by means of the second law
Vocal-visual combinations in wild chimpanzees
Living organisms throughout the animal kingdom habitually communicate with multi-modal signals that use multiple sensory channels. Such composite signals vary in their communicative function, as well as the extent to which they are recombined freely. Humans typically display complex forms of multi-modal communication, yet the evolution of this capacity remains unknown. One of our two closest living relatives, chimpanzees, also produce multi-modal combinations and therefore may offer a valuable window into the evolutionary roots of human communication. However, a currently neglected step in describing multi-modal systems is to disentangle non-random combinations from those that occur simply by chance. Here we aimed to provide a systematic quantification of communicative behaviour in our closest living relatives, describing non-random combinations produced across auditory and visual modalities. Through recording the behaviour of wild chimpanzees from the Kibale forest, Uganda we generated the first repertoire of non-random combined vocal and visual components. Using collocation analysis, we identified more than 100 vocal-visual combinations which occurred more frequently than expected by chance. We also probed how multi-modal production varied in the population, finding no differences in the number of visual components produced with vocalisations as a function of age, sex or rank. As expected, chimpanzees produced more visual components alongside vocalizations during longer vocalization bouts, however, this was only the case for some vocalization types, not others. We demonstrate that chimpanzees produce a vast array of combined vocal and visual components, exhibiting a hitherto underappreciated level of multi-modal complexity
Quality Over Quantity: Advantages of Using Alpha-Synuclein Preformed Fibril Triggered Synucleinopathy to Model Idiopathic Parkinson’s Disease
Animal models have significantly advanced our understanding of Parkinson’s disease (PD). Alpha-synuclein (α-syn) has taken center stage due to its genetic connection to familial PD and localization to Lewy bodies, one pathological hallmark of PD. Animal models developed on the premise of elevated alpha-synuclein via germline manipulation or viral vector-mediated overexpression are used to investigate PD pathophysiology and vet novel therapeutics. While these models represented a step forward compared to their neurotoxicant model predecessors, they rely on overexpression of supraphysiological levels of α-syn to trigger toxicity. However, whereas SNCA-linked familial PD is associated with elevated α-syn, elevated α-syn is not associated with idiopathic PD. Therefore, the defining feature of the α-syn overexpression models may fail to appropriately model idiopathic PD. In the last several years a new model has been developed in which α-syn preformed fibrils are injected intrastriatally and trigger normal endogenous levels of α-syn to misfold and accumulate into Lewy body-like inclusions. Following a defined period of inclusion accumulation, distinct phases of neuroinflammation and progressive degeneration can be detected in the nigrostriatal system. In this perspective, we highlight the fact that levels of α-syn achieved in overexpression models generally exceed those observed in idiopathic and even SNCA multiplication-linked PD. This raises the possibility that supraphysiological α-syn expression may drive pathophysiological mechanisms not relevant to idiopathic PD. We argue in this perspective that synucleinopathy triggered to form within the context of normal α-syn expression represents a more faithful animal model of idiopathic PD when examining the role of neuroinflammation or the relationship between a-syn aggregation and toxicity
Beyond Bacteria: A Study of the Enteric Microbial Consortium in Extremely Low Birth Weight Infants
Extremely low birth weight (ELBW) infants have high morbidity and mortality, frequently due to invasive infections from bacteria, fungi, and viruses. The microbial communities present in the gastrointestinal tracts of preterm infants may serve as a reservoir for invasive organisms and remain poorly characterized. We used deep pyrosequencing to examine the gut-associated microbiome of 11 ELBW infants in the first postnatal month, with a first time determination of the eukaryote microbiota such as fungi and nematodes, including bacteria and viruses that have not been previously described. Among the fungi observed, Candida sp. and Clavispora sp. dominated the sequences, but a range of environmental molds were also observed. Surprisingly, seventy-one percent of the infant fecal samples tested contained ribosomal sequences corresponding to the parasitic organism Trichinella. Ribosomal DNA sequences for the roundworm symbiont Xenorhabdus accompanied these sequences in the infant with the greatest proportion of Trichinella sequences. When examining ribosomal DNA sequences in aggregate, Enterobacteriales, Pseudomonas, Staphylococcus, and Enterococcus were the most abundant bacterial taxa in a low diversity bacterial community (mean Shannon-Weaver Index of 1.02±0.69), with relatively little change within individual infants through time. To supplement the ribosomal sequence data, shotgun sequencing was performed on DNA from multiple displacement amplification (MDA) of total fecal genomic DNA from two infants. In addition to the organisms mentioned previously, the metagenome also revealed sequences for gram positive and gram negative bacteriophages, as well as human adenovirus C. Together, these data reveal surprising eukaryotic and viral microbial diversity in ELBW enteric microbiota dominated bytypes of bacteria known to cause invasive disease in these infants
- …