208 research outputs found
Generalised Einstein Relation for Hot Brownian Motion
The Brownian motion of a hot nanoparticle is described by an effective Markov
theory based on fluctuating hydrodynamics. Its predictions are scrutinized over
a wide temperature range using large-scale molecular dynamics simulations of a
hot nanoparticle in a Lennard-Jones fluid. The particle positions and momenta
are found to be Boltzmann distributed according to distinct effective
temperatures and . For we
derive a formally exact theoretical prediction and establish a generalised
Einstein relation that links it to directly measurable quantities
Hot Brownian Motion
We derive the generalized Markovian description for the non-equilibrium
Brownian motion of a heated particle in a simple solvent with a
temperature-dependent viscosity. Our analytical results for the generalized
fluctuation-dissipation and Stokes-Einstein relations compare favorably with
measurements of laser-heated gold nano-particles and provide a practical
rational basis for emerging photothermal technologies.Comment: 10 pages, 5 figure
Survey of the Moths (Lepidoptera) Inhabiting the Funk Bottoms Wildlife Area, Wayne and Ashland Counties, Ohio
Author Institution: Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State UniversityIn 1995, the Funk Bottoms Wildlife Area was the subject of an ongoing series of insect surveys intended to establish benchmark information on arthropod diversity of wetlands in northeast Ohio. This article concentrates on the moths which were collected at ultraviolet light traps within the Funk Bottoms Wildlife Area. A companion report will follow focusing on the Coleoptera along with several orders of aquatic insects. 3252 specimens were identified to 306 species in 19 families. These species are classified as follows: Abundant = 34; Locally Abundant = 1; Common = 257; Locally Common = 2; Uncommon = 10; Rare = 1; and Special Interest = 1
Pharmacological and Parenteral Nutrition-Based Interventions in Microvillus Inclusion Disease
Microvillus inclusion disease (MVID) is a rare inherited and invariably fatal enteropathy, characterized by severe intractable secretory diarrhea and nutrient malabsorption. No cure exists, and patients typically die during infancy because of treatment-related complications. The need for alternative treatment strategies is evident. Several pharmacological interventions with variable successes have been tried and reported for individual patients as part of their clinical care. Unfortunately, these interventions and their outcomes have remained hidden in case reports and have not been reviewed. Further, recent advances regarding MVID pathogenesis have shed new light on the outcomes of these pharmacological interventions and offer suggestions for future clinical research and trials. Hence, an inventory of reported pharmacological interventions in MVID, their rationales and outcomes, and a discussion of these in the light of current knowledge is opportune. Together with a discussion on MVID-specific pharmacokinetic, -dynamic, and -genetic concerns that pose unique challenges regarding pharmacological strategies, we envision that this paper will aid researchers and clinicians in their efforts to develop pharmacological interventions to combat this devastating disease
A two-species continuum model for aeolian sand transport
Starting from the physics on the grain scale, we develop a simple continuum
description of aeolian sand transport. Beyond popular mean-field models, but
without sacrificing their computational efficiency, it accounts for both
dominant grain populations, hopping (or "saltating") and creeping (or
"reptating") grains. The predicted stationary sand transport rate is in
excellent agreement with wind tunnel experiments simulating wind conditions
ranging from the onset of saltation to storms. Our closed set of equations thus
provides an analytically tractable, numerically precise, and computationally
efficient starting point for applications addressing a wealth of phenomena from
dune formation to dust emission.Comment: 23 pages, 9 figure
Nanoscale temperature measurements using non-equilibrium Brownian dynamics of a levitated nanosphere
Einstein realised that the fluctuations of a Brownian particle can be used to
ascertain properties of its environment. A large number of experiments have
since exploited the Brownian motion of colloidal particles for studies of
dissipative processes, providing insight into soft matter physics, and leading
to applications from energy harvesting to medical imaging. Here we use
optically levitated nanospheres that are heated to investigate the
non-equilibrium properties of the gas surrounding them. Analysing the sphere's
Brownian motion allows us to determine the temperature of the centre-of-mass
motion of the sphere, its surface temperature and the heated gas temperature in
two spatial dimensions. We observe asymmetric heating of the sphere and gas,
with temperatures reaching the melting point of the material. This method
offers new opportunities for accurate temperature measurements with spatial
resolution on the nanoscale, and a new means for testing non-equilibrium
thermodynamicsComment: 5 pages, 4 figures, supplementary material available upon reques
Anthropometrics and fat mass, but not fat-free mass, are compromised in infants requiring parenteral nutrition after neonatal intestinal surgery
BACKGROUND: Children with intestinal failure (IF) receiving long-term parenteral nutrition (PN) have altered body composition (BC), but data on BC changes from start of PN onwards are lacking. OBJECTIVE: We aimed to assess growth and BC in infants after neonatal intestinal surgery necessitating PN and at risk for IF, and to explore associations with clinical parameters. DESIGN: Prospective cohort study in infants after intestinal surgery. IF was defined as PN-dependency for > 60 days. Standard deviation scores (SDS) for anthropometry were calculated until 6 months corrected age. In a subgroup, fat mass (FM) and fat-free mass (FFM) were measured with air-displacement plethysmography at 2- and 6-months corrected age. SDS for length-adjusted FM index and FFM index were calculated. Associations between cumulative amount of PN and BC parameters were analyzed with linear mixed-effect models. RESULTS: Ninety-five neonates were included (54% male, 35% born < 32 weeks). Thirty-nine infants (41%) had IF. Studied infants had compromised anthropometric parameters during follow-up. At 6 months corrected age, they remained smaller (median weight-for-age SDS -0.9 [interquartile range -1.5, 0.1], P < 0.001) than the normal population. In 57 infants, 93 BC measurements were performed. FM index SDS was lower than in healthy infants at 2- and 6-months corrected age (-0.9 [-1.6, -0.3], P < 0.001 and -0.7 [-1.3, 0.1], P = 0.001, respectively), but FFM index SDS did not differ. A higher cumulative amount of PN predicted higher FM index in female infants but lower FM index in male infants. CONCLUSIONS: In this cohort of infants receiving PN after intestinal surgery, compromised anthropometrics, decreased FM and adequate FFM were observed during the first 6 months. Male and female infants seemed to respond differently to PN when it comes to FM index. Continuing growth monitoring after 6 months of age is strongly recommended, while further research should explore the benefit of incorporating ongoing BC monitoring during follow-up.Clinical Trial Registration: Dutch Trial Register NTR6080, https://www.trialregister.nl/trial/5892
Animal movements in the Kenya Rift and evidence for the earliest ambush hunting by hominins
Animal movements in the Kenya Rift Valley today are influenced by a combination of topography and trace nutrient distribution. These patterns would have been the same in the past when hominins inhabited the area. We use this approach to create a landscape reconstruction of Olorgesailie, a key site in the East African Rift with abundant evidence of large-mammal butchery between ~1.2 and ~0.5 Ma BP. The site location in relation to limited animal routes through the area show that hominins were aware of animal movements and used the location for ambush hunting during the Lower to Middle Pleistocene. These features explain the importance of Olorgesailie as a preferred location of repeated hominin activity through multiple changes in climate and local environmental conditions, and provide insights into the cognitive and hunting abilities of Homo erectus while indicating that their activities at the site were aimed at hunting, rather than scavenging
MYO5B, STX3, and STXBP2 mutations reveal a common disease mechanism that unifies a subset of congenital diarrheal disorders:A mutation update
Microvillus inclusion disease (MVID) is a rare but fatal autosomal recessive congenital diarrheal disorder caused by MYO5B mutations. In 2013, we launched an open-access registry for MVID patients and their MYO5B mutations (www.mvid-central.org). Since then, additional unique MYO5B mutations have been identified in MVID patients, but also in non-MVID patients. Animal models have been generated that formally prove the causality between MYO5B and MVID. Importantly, mutations in two other genes, STXBP2 and STX3, have since been associated with variants of MVID, shedding new light on the pathogenesis of this congenital diarrheal disorder. Here, we review these additional genes and their mutations. Furthermore, we discuss recent data from cell studies that indicate that the three genes are functionally linked and, therefore, may constitute a common disease mechanism that unifies a subset of phenotypically linked congenital diarrheal disorders. We present new data based on patient material to support this. To congregate existing and future information on MVID geno-/phenotypes, we have updated and expanded the MVID registry to include all currently known MVID-associated gene mutations, their demonstrated or predicted functional consequences, and associated clinical information.</p
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