Shark Diversity and Relative Abundance at Myrtle Beach, SC Fishing Piers

Sharks are frequently observed at fishing piers (Barwick et al. 2004; Martin et al. 2019). These piers offer structural habitats for shark prey items, such as smaller fish and invertebrates, which can attract sharks to piers (Barwick et al. 2004; Heupel 2005). Additionally, fishers often clean their catch and discard entrails at the pier, which also may attract sharks (Martin et al. 2019). Moreover, other factors could play a role in attracting sharks to piers. These include water quality parameters, like salinity and temperature, and the physical characteristics of the pier (Ulrich et al. 2007; Castro 1996; Heupel 2005)

What are the Most Commonly Used Tools to Screen Depression in HIV-Infected Gay and Bisexual Men?

Gay and bisexual men infected with human immunodeficiency virus (HIV) comprise a sizable, medically vulnerable population. Depression is the most commonly experienced mental health disorder affecting this group of people, lending itself to a host of risks associated with depression. As screening of depression in this population can be challenging, it is vital that clinicians have the best available tools and guidelines to detect depressive symptomology. This focused, comprehensive review of the literature examined current data describing the clinical instruments used to detect depressive symptoms in HIV-infected gay and bisexual men. The aim of this analysis was to seek out which instruments were the most widely and successfully employed for this population. An initial search using EBSCOhost and associated databases CINAHL, MEDLINE, PsycINFO, and Health and Psychosocial Instruments alongside inclusion and exclusion criteria found 1,899 articles. Results were narrowed using additional inclusion and exclusion criteria and relevancy, yielding a total of 13 articles for review. The findings of this review suggest screening of depressive symptoms in HIV-infected gay and bisexual men was most successful using the CES-D, the BSI-18, and the BDI. Health care providers should have an understanding of the importance in assessing this population for depression and have access to the best possible tools to do so

Occurrence and Treatment of Bone Atrophic Non-Unions Investigated by an Integrative Approach

Recently developed atrophic non-union models are a good representation of the clinical situation in which many nonunions develop. Based on previous experimental studies with these atrophic non-union models, it was hypothesized that in order to obtain successful fracture healing, blood vessels, growth factors, and (proliferative) precursor cells all need to be present in the callus at the same time. This study uses a combined in vivo-in silico approach to investigate these different aspects (vasculature, growth factors, cell proliferation). The mathematical model, initially developed for the study of normal fracture healing, is able to capture essential aspects of the in vivo atrophic non-union model despite a number of deviations that are mainly due to simplifications in the in silico model. The mathematical model is subsequently used to test possible treatment strategies for atrophic non-unions (i.e. cell transplant at post-osteotomy, week 3). Preliminary in vivo experiments corroborate the numerical predictions. Finally, the mathematical model is applied to explain experimental observations and identify potentially crucial steps in the treatments and can thereby be used to optimize experimental and clinical studies in this area. This study demonstrates the potential of the combined in silico-in vivo approach and its clinical implications for the early treatment of patients with problematic fractures

Speedy stomata, photosynthesis and plant water use efficiency

Stomatal movements control CO₂ uptake for photosynthesis and water loss through transpiration, and therefore play a key role in plant productivity and water use efficiency. The predicted doubling of global water usage by 2030 mean that stomatal behaviour is central to current efforts to increase photosynthesis and crop yields, particularly under conditions of reduced water availability. In the field, slow stomatal responses to dynamic environmental conditions add a temporal dimension to gaseous fluxes between the leaf and atmosphere. Here, we review recent work on the rapidity of stomatal responses and present some of the possible anatomical and biochemical mechanisms that influence the rapidity of stomatal movements

Determination of surface densities from a combination of gravimetry and satellite altimetry

Prepared for Air Force Cambridge Research Laboratories, Air Force Systems Command, United States Air Force, Bedford, Massachusetts: Contract No. F19628-72-C-0120, Project No. 8607, Task No. 860701The utilization of satellite altimetry by itself, and in combination with existing gravity material is considered for the determination of the gravity field of the earth. This is done by developing equations that relate surface density values defined in discrete blocks to geoid undulations and gravity anomalies. The use of a higher order reference field defined by a set of spherical harmonics is considered and truncation errors are computed when the contribution of an area outside a spherical cap is obtained from a spherical harmonic expansion of the anomaly field. A suggested solution to recover 5° equal area blocks is made with specific recommendations made on the ordering of these blocks so that structured sets of normal equations will result. The determination of a more local field (such as 1°) is discussed using the global 5° field as a basis

Modeling size segregation of bidisperse granular flow: the roles of segregation, advection, and diffusion

Segregation of granular materials composed of different-sized particles has important repercussions in various industrial processes and natural phenomena, but predicting size segregation remains a challenging problem. To address this problem, we have developed a theoretical model that captures the interplay between advection, segregation, and diffusion in size bidisperse granular materials. The fluxes associated with these three driving factors depend on the underlying kinematics, whose characteristics play key roles in determining particle segregation configurations. Unlike earlier models for segregation, our model uses parameters based on kinematics from discrete element method simulations instead of arbitrarily adjustable fitting parameters, and it achieves excellent quantitative agreement with both experimental and simulation results when applied to quasi-two dimensional bounded heaps and circular rotating tumblers. The model yields two dimensionless control parameters, both of which are only functions of control parameters (feed rate, particle sizes, and system size) and kinematic parameters (diffusion coefficient, flowing layer depth, and percolation velocity). The Péclet number, Pe, captures the interplay of advection and diffusion, and the second dimensionless parameter, Λ, describes the interplay between segregation and advection. A parametric study of Λ and Pe demonstrates how particle segregation configuration depends on the interplay of advection, segregation, and diffusion. In bounded heap flow, the particle segregation configurations are determined by advection, segregation, and diffusion depending on flow conditions and particle properties. In contrast, in circular tumbler flow, the final particle segregation configurations depend primarily on the competition between segregation and diffusion, and segregation rates are determined by advection and the flowing layer thickness. ACKNOWLEDGEMENTS We gratefully acknowledge financial support from The Dow Chemical Compan

Predicting polydisperse granular segregation

Most granular materials in industrial applications and natural settings are size-polydisperse, but most models and simulations of segregation consider only bidisperse particle distributions. Here, we extend our recently developed theoretical advection–diffusion–segregation model to polydisperse particle distributions. To test the theoretical approach, we model and simulate grains log-normally distributed by size in a chute flow. In steady state, material near the free surface is dominated by large particles, whereas the lower regions are composed of mostly small particles. The segregation pattern depends on a single dimensionless control parameter, which is a function of the particle sizes, the diffusion coefficient, the shear rate, and the flowing layer depth. Interestingly, for all values of the control parameter, the overall log normal particle size distribution is approximately maintained at each spatial location, but with different mean and variance than the overall particle distribution. To confirm the theoretical results, we use discrete element method (DEM) simulations using a general purpose graphics processing unit. Quantitative agreement is found between theory and DEM simulations. Funded by the Dow Chemical Company

Aortic valvuloplasty of calcific aortic stenosis with monofoil and trefoil balloon catheters: practical considerations

In order to evaluate the relation between balloon design (monofoil, trefoil) and valvular configuration, experimental aortic valvuloplasty was performed in four post-mortem hearts with calcific aortic sten