Biological reference points for Atlantic surfclam (Spisula solidissima) in warming seas

Atlantic surfclam (Spisula solidissima) are a large, commercially important shellfish in the United States faced with several important management challenges. Compared to many harvested fish and shellfish, their life history is relatively unknown. They are undergoing contraction in the southern and inshore parts of their range, as well as expansion into deeper water. Atlantic surfclam are thermally sensitive, and the changes in their distribution track changes in maximum bottom temperature. Sessile species cannot emigrate and are limited to recruitment and mortality as mechanisms for redistribution in response to changing climate. Management of Atlantic surf clam should account for these challenges. We describe a simulation designed to calculate biological reference points that will work well for Atlantic surfclam relative to biological and fishery goals, over a range of life history parameters, assessment uncertainties, and increases in temperature. Simulations of the trade-off between somatic growth and mortality under increased temperature led to target fishing mortality rates higher than the status quo, but also to increased variability in yield. Results suggest that increasing temperature may adversely affect the Atlantic surfclam industry, which prefers stable catches to short term increases in yield, due to market limitations. The results of this analysis are specific to Atlantic surfclam, but the methods described here could be used to enhance management for other harvested species facing similar challenges

Combinatorial Bounds and Characterizations of Splitting Authentication Codes

We present several generalizations of results for splitting authentication codes by studying the aspect of multi-fold security. As the two primary results, we prove a combinatorial lower bound on the number of encoding rules and a combinatorial characterization of optimal splitting authentication codes that are multi-fold secure against spoofing attacks. The characterization is based on a new type of combinatorial designs, which we introduce and for which basic necessary conditions are given regarding their existence.Comment: 13 pages; to appear in "Cryptography and Communications

High-Resolution Morphological Characterization Investigation On The Effects Of Local Malaysian Condiments On Human Mineralized Tissues.

There are a huge variety of locally produced Malaysian sauces available in the local market. In many instances they may formed the everyday condiments of the main menu especially during lunch and dinner to the local Malaysian citizen

Patient Safety in Interventional Radiology: A CIRSE IR Checklist

Interventional radiology (IR) is an invasive speciality with the potential for complications as with other invasive specialities. The World Health Organization (WHO) produced a surgical safety checklist to decrease the morbidity and mortality associated with surgery. The Cardiovascular and Interventional Society of Europe (CIRSE) set up a task force to produce a checklist for IR. Use of the checklist will, we hope, reduce the incidence of complications after IR procedures. It has been modified from the WHO surgical safety checklist and the RAD PASS from Holland

Diffuse small bowel thickening in aids patient - a case report

<p>Abstract</p> <p>Background</p> <p>Diarrhea is common in HIV/AIDS patients, caused by both classic enteric pathogens and different opportunistic agents. <it>Infection with these different pathogens may lead to similar radiological findings, thus causing diagnostic confusion</it>.</p> <p>Case presentation</p> <p>A 30-yr-old female with AIDS presented with chronic diarrhea of 4 months duration. She had diffuse small bowel thickening present on CT scan of her abdomen, with stool examination showing no parasites. She was erroneously diagnosed as abdominal tuberculosis and given antituberculosis drugs with which she showed no improvement. Repeat stool examination later at a specialized laboratory revealed <it>Cryptosporidium parvum </it>infection.</p> <p>The patient was given an extended course of nitazoxanide treatment, as her stool examination was positive for <it>Cryptosporidium parvum </it>even after 2 weeks of drug consumption. Parasite clearance was documented after 10 weeks of treatment. Interestingly, the bowel thickening reversed with parasitological clearance.</p> <p>Conclusions</p> <p><it>Cryptosporidium parvum </it>may lead to small bowel thickening in AIDS patients. This small bowel thickening may reverse following parasitological clearance.</p

Carboxyhaemoglobin levels and their determinants in older British men

Background: Although there has been concern about the levels of carbon monoxide exposure, particularly among older people, little is known about COHb levels and their determinants in the general population. We examined these issues in a study of older British men.Methods: Cross-sectional study of 4252 men aged 60-79 years selected from one socially representative general practice in each of 24 British towns and who attended for examination between 1998 and 2000. Blood samples were measured for COHb and information on social, household and individual factors assessed by questionnaire. Analyses were based on 3603 men measured in or close to (< 10 miles) their place of residence.Results: The COHb distribution was positively skewed. Geometric mean COHb level was 0.46% and the median 0.50%; 9.2% of men had a COHb level of 2.5% or more and 0.1% of subjects had a level of 7.5% or more. Factors which were independently related to mean COHb level included season (highest in autumn and winter), region (highest in Northern England), gas cooking (slight increase) and central heating (slight decrease) and active smoking, the strongest determinant. Mean COHb levels were more than ten times greater in men smoking more than 20 cigarettes a day (3.29%) compared with non-smokers (0.32%); almost all subjects with COHb levels of 2.5% and above were smokers (93%). Pipe and cigar smoking was associated with more modest increases in COHb level. Passive cigarette smoking exposure had no independent association with COHb after adjustment for other factors. Active smoking accounted for 41% of variance in COHb level and all factors together for 47%.Conclusion: An appreciable proportion of men have COHb levels of 2.5% or more at which symptomatic effects may occur, though very high levels are uncommon. The results confirm that smoking (particularly cigarette smoking) is the dominant influence on COHb levels

Geometric Multicut: Shortest Fences for Separating Groups of Objects in the Plane

We study the following separation problem: Given a collection of pairwise disjoint coloured objects in the plane with k different colours, compute a shortest “fence” F, i.e., a union of curves of minimum total length, that separates every pair of objects of different colours. Two objects are separated if F contains a simple closed curve that has one object in the interior and the other in the exterior. We refer to the problem as GEOMETRIC k-CUT, as it is a geometric analog to the well-studied multicut problem on graphs. We first give an O(n4log3n)-time algorithm that computes an optimal fence for the case where the input consists of polygons of two colours with n corners in total. We then show that the problem is NP-hard for the case of three colours. Finally, we give a randomised 4/3⋅1.2965-approximation algorithm for polygons and any number of colours

Isotopic variation of parity violation in atomic ytterbium

We report on measurements of atomic parity violation, made on a chain of ytterbium isotopes with mass numbers A=170, 172, 174, and 176. In the experiment, we optically excite the 6s2 1S0 -> 5d6s 3D1 transition in a region of crossed electric and magnetic fields, and observe the interference between the Stark- and weak-interaction-induced transition amplitudes, by making field reversals that change the handedness of the coordinate system. This allows us to determine the ratio of the weak-interaction-induced electric-dipole (E1) transition moment and the Stark-induced E1 moment. Our measurements, which are at the 0.5% level of accuracy for three of the four isotopes measured, allow a definitive observation of the isotopic variation of the weak-interaction effects in an atom, which is found to be consistent with the prediction of the Standard Model. In addition, our measurements provide information about an additional Z' boson.Comment: 19 pages, 4 figures, 2 table

Three-dimensional femtosecond laser nanolithography of crystals

Nanostructuring hard optical crystals has so far been exclusively feasible at their surface, as stress induced crack formation and propagation has rendered high precision volume processes ineffective. We show that the inner chemical etching reactivity of a crystal can be enhanced at the nanoscale by more than five orders of magnitude by means of direct laser writing. The process allows to produce cm-scale arbitrary three-dimensional nanostructures with 100 nm feature sizes inside large crystals in absence of brittle fracture. To showcase the unique potential of the technique, we fabricate photonic structures such as sub-wavelength diffraction gratings and nanostructured optical waveguides capable of sustaining sub-wavelength propagating modes inside yttrium aluminum garnet crystals. This technique could enable the transfer of concepts from nanophotonics to the fields of solid state lasers and crystal optics.Comment: Submitted Manuscript and Supplementary Informatio

Las TIC’S, una herramienta para la competitividad educativa durante la pandemia por covid-19

The objective of this work is to analyze the different ICT tools in distance education teaching strategies during the COVID-19 pandemic in basic education schools in the state of Colima, with the intention of identifying their impact on educational competitiveness by relating the variables dropout and school failure, the most important axes within the educational indicators of a country and therefore of a state. With this, a reflection on the Technological Humanist approach can be made, which is the basis for this work, with the idea of substantiating that ICTs are a tool that promotes educational competitiveness. In this research, the analytical-descriptive method was used where 374 cases of 34 state schools were studied, resulting in a statistic that was maintained from previous cycles to the current one, therefore it can be concluded that ICTs do have a favorable impact on the variables of school dropout and failure.El objetivo de este trabajo es analizar las distintas herramientas TICs en las estrategias docentes de educación a distancia durante la pandemia por COVID-19 en escuelas de educación básica del estado de Colima, con la intención de identificar su impacto en la competitividad educativa relacionando las variables de abandono y reprobación escolar, los ejes más importantes dentro los indicadores educativos de un país y por ende de un estado. Con esto, se puede hacer una reflexión sobre el enfoque Humanista Tecnológico el cuál es base para este trabajo, con la idea de fundamentar que las TIC son una herramienta que impulsa la competitividad educativa. En esta investigación se utilizó el método analítico – descriptivo en donde se estudiaron 374 casos de 34 escuelas estatales, dando como resultado una estadística que se mantuvo de ciclos anteriores al actual, por ende se puede concluir que las TICs si inciden de manera favorable en las variables de abandono y reprobación escolar