Temporal Dynamics of Visual Attention Allocation

We often temporally prepare our attention for an upcoming event such as a starter pistol. In such cases, our attention should be properly allocated around the expected moment of the event to process relevant sensory input efficiently. In this study, we examined the dynamic changes of attention levels near the expected moment by measuring contrast sensitivity to a target that was temporally cued by a five-second countdown. We found that the overall attention level decreased rapidly after the expected moment, while it stayed relatively constant before it. Results were not consistent with the predictions of existing explanations of temporal attention such as the hazard rate or the stimulus-driven oscillations. A control experiment ruled out the possibility that the observed pattern was due to biased time perception. In a further experiment with a wider range of cue-stimulus-intervals, we observed that attention level increased until the last 500 ms of the interval range, and thereafter, started to decrease. Based on the performances of a generative computational model, we suggest that our results reflect the nature of temporal attention that takes into account the subjectively estimated hazard rate and the probability of relevant events occurring in the near future

Etiopathogenic features of acne vulgaris

Acne vulgaris is one of the most frequent dermatoses in the general population. Numerous scientific articles are available on acne, mostly relating to its etiopathogeny. This notwithstanding, the large amount of scientific information generated by works on acne vulgaris has made it difficult to converge knowledge on its etiopathogeny into a single understanding. Therefore, this review has been proposed to analyze the four classic mechanisms of this dermatosis (sebum production, follicular hyperkeratinization, bacterial colonization and glandular inflammation), as well as its secondary mechanism, namely hormonal mediation.A acne vulgar é uma das dermatoses mais freqüentes na população em geral. Encontra-se na literatura grande número de trabalhos científicos referentes sobretudo a sua etiopatogenia. No entanto, dado o grande número de informações geradas a respeito, dificilmente consegue-se reuni-las em entendimento comum. Esta revisão literária foi proposta a fim de abordar os mecanismos etiopatogênicos clássicos da acne vulgar (produção sebácea, hiperqueratinização folicular, colonização bacteriana folicular e inflamação glandular) e o mecanismo coadjuvante principal, a influência hormonal.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Depto. de DermatologiaPontifícia Universidade Católica de Campinas Hospital e Maternidade Celso Pierro Serviço de DermatologiaUNIFESP, EPM, Depto. de DermatologiaSciEL

Population‐based cohort study of outcomes following cholecystectomy for benign gallbladder diseases

Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‐cause 30‐day readmissions and complications in a prospective population‐based cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‐cause 30‐day readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‐level hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16·3 per cent) were performed as an emergency, 4165 (46·8 per cent) as elective operations, and 3293 patients (37·0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7·1 per cent (633 of 8909) and 10·8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics

Wired for Her Face? Male Attentional Bias for Female Faces

Under conditions of inattention or deficits in orienting attention, special classes of stimuli (e.g. faces, bodies) are more likely to be perceived than other stimuli. This suggests that biologically salient visual stimuli automatically recruit attention, even when they are task-irrelevant or ignored. Here we report results from a behavioral experiment with female and male subjects and two magnetoencephalography (MEG) experiments with male subjects only, in which we investigated attentional capture with face and hand stimuli. In both the behavioral and MEG experiments, subjects were required to count the number of gender-specific targets from either face or hand categories within a block of stimuli. In the behavioral experiment, we found that male subjects were significantly more accurate in response to female than male face target blocks. There was no corresponding effect found in response to hand target blocks. Female subjects did not show a gender-based difference in response to face or hand target blocks. MEG results indicated that the male subjects’ responses to face stimuli in primary visual cortex (V1) and the face-selective part of the fusiform gyrus (FG) were reduced when male face stimuli were not relevant to the task, whereas female faces maintained a strong response in these areas in both task-relevant and task-irrelevant conditions. These results suggest that within the male brain, female face stimuli are more resilient to suppression than male faces, once attention is drawn to the part of the visual field where the face appears

A Multi-Center, Qualitative Assessment of Pediatrician and Maternal Perspectives on Rotavirus Vaccines and the Detection of Porcine circovirus

<p>Abstract</p> <p>Background</p> <p>In 2010, researchers using novel laboratory techniques found that US-licensed rotavirus vaccines contain DNA or DNA fragments from <it>Porcine circovirus </it>(PCV), a virus common among pigs but not believed to cause illness in humans. We sought to understand pediatricians' and mothers' perspectives on this finding.</p> <p>Methods</p> <p>We conducted three iterations of focus groups for pediatricians and non-vaccine hesitant mothers in Seattle, WA, Cincinnati, OH, and Rochester, NY. Focus groups explored perceptions of rotavirus disease, rotavirus vaccination, and attitudes about the detection of PCV material in rotavirus vaccines.</p> <p>Results</p> <p>Pediatricians understood firsthand the success of rotavirus vaccines in preventing severe acute gastroenteritis among infants and young children. They measured this benefit against the theoretical risk of DNA material from PCV in rotavirus vaccines, determining overall that the PCV finding was of no clinical significance. Particularly influential was the realization that the large, randomized clinical trials that found both vaccines to be highly effective and safe were conducted with DNA material from PCV already in the vaccines.</p> <p>Most mothers supported the ideal of full disclosure regarding vaccination risks and benefits. However, with a scientific topic of this complexity, simplified information regarding PCV material in rotavirus vaccines seemed frightening and suspicious, and detailed information was frequently overwhelming. Mothers often remarked that if they did not understand a medical or technical topic regarding their child's health, they relied on their pediatrician's guidance.</p> <p>Many mothers and pediatricians were also concerned that persons who abstain from pork consumption for religious or personal reasons may have unsubstantiated fears of the PCV finding.</p> <p>Conclusions</p> <p>Pediatricians considered the detection of DNA material from PCV in rotavirus vaccines a "non-issue" and reported little hesitation in continuing to recommend the vaccines. Mothers desired transparency, but ultimately trusted their pediatrician's recommendation. Both vaccines are currently approved for their intended use, and no risk of human PCV illness has been reported. Communicating this topic to pediatricians and mothers requires sensitivity to a broad range of technical understanding and personal concerns.</p

The Evolution of Extracellular Fibrillins and Their Functional Domains

Fibrillins constitute the major backbone of multifunctional microfibrils in elastic and non-elastic extracellular matrices, and are known to interact with several binding partners including tropoelastin and integrins. Here, we study the evolution of fibrillin proteins. Following sequence collection from 39 organisms representative of the major evolutionary groups, molecular evolutionary genetics and phylogeny inference software were used to generate a series of evolutionary trees using distance-based and maximum likelihood methods. The resulting trees support the concept of gene duplication as a means of generating the three vertebrate fibrillins. Beginning with a single fibrillin sequence found in invertebrates and jawless fish, a gene duplication event, which coincides with the appearance of elastin, led to the creation of two genes. One of the genes significantly evolved to become the gene for present-day fibrillin-1, while the other underwent evolutionary changes, including a second duplication, to produce present-day fibrillin-2 and fibrillin-3. Detailed analysis of several sequences and domains within the fibrillins reveals distinct similarities and differences across various species. The RGD integrin-binding site in TB4 of all fibrillins is conserved in cephalochordates and vertebrates, while the integrin-binding site within cbEGF18 of fibrillin-3 is a recent evolutionary change. The proline-rich domain in fibrillin-1, glycine-rich domain in fibrillin-2 and proline-/glycine-rich domain in fibrillin-3 are found in all analyzed tetrapod species, whereas it is completely replaced with an EGF-like domain in cnidarians, arthropods, molluscs and urochordates. All collected sequences contain the first 9-cysteine hybrid domain, and the second 8-cysteine hybrid domain with exception of arthropods containing an atypical 10-cysteine hybrid domain 2. Furin cleavage sites within the N- and C-terminal unique domains were found for all analyzed fibrillin sequences, indicating an essential role for processing of the fibrillin pro-proteins. The four cysteines in the unique N-terminus and the two cysteines in the unique C-terminus are also highly conserved

Chemotaxis of Cell Populations through Confined Spaces at Single-Cell Resolution

Cell migration is crucial for both physiological and pathological processes. Current in vitro cell motility assays suffer from various drawbacks, including insufficient temporal and/or optical resolution, or the failure to include a controlled chemotactic stimulus. Here, we address these limitations with a migration chamber that utilizes a self-sustaining chemotactic gradient to induce locomotion through confined environments that emulate physiological settings. Dynamic real-time analysis of both population-scale and single-cell movement are achieved at high resolution. Interior surfaces can be functionalized through adsorption of extracellular matrix components, and pharmacological agents can be administered to cells directly, or indirectly through the chemotactic reservoir. Direct comparison of multiple cell types can be achieved in a single enclosed system to compare inherent migratory potentials. Our novel microfluidic design is therefore a powerful tool for the study of cellular chemotaxis, and is suitable for a wide range of biological and biomedical applications

Measurement of the Rates of Synthesis of Three Components of Ribosomes of Mycobacterium fortuitum: A Theoretical Approach to qRT-PCR Experimentation

BACKGROUND: Except for the ribosomal protein L12 (rplL), ribosomal proteins are present as one copy per ribosome; L12 (rplL) is unusual because it is present as four copies per ribosome. Thus, the strategies used by Mycobacterium fortuitum to regulate ribosomal protein synthesis were investigated, including evaluations of the rates of chain elongations of 16S rRNA, rplL and ribosomal protein S12 (rpsL). METHODOLOGY: RNA was isolated from cell cultures and cDNA was prepared. The numbers of cDNA copies of 16S rRNA, precursor-16S rRNA and transcripts of rpsL and rplL were quantified by qRT-PCR and then related to the rates of 16S rRNA, rpsL and rplL chain elongations by means of a mathematical framework for coupled transcription/translation. PRINCIPAL FINDINGS: The rates of synthesis of 16S rRNA, rpsL and rplL respectively were found to be approximately 50 x 10(3) nucleotides h(-1), 1.6 x 10(3) amino acid residues h(-1) and 3.4 x 10(3) amino acid residues h(-1). The number of transcripts of rplL was approximately twice that of rpsL. These data account for the presence of one copy of rpsL and four copies of rplL per ribosome, and reveal that the rate of M. fortuitum ribosome synthesis was closer to that of M. tuberculosis than to E. coli. Except for rplJ, the elongation rate obtained for rpsL was inferred to be appropriate for all other proteins present as one copy per ribosome. SIGNIFICANCE: The results obtained provide the basis for a comprehensive view of the kinetics of ribosome synthesis, and of the ways that bacterial cells utilize genes encoding ribosomal proteins. The methodology also applies to proteins involved in transcription, energy generation and to bacterial proteins in general. The method proposed for measuring the fidelity of cDNA preparations is intrinsically much more sensitive than procedures that measure the integrity of 16S rRNA

Birds of a Feather Flock Together: Experience-Driven Formation of Visual Object Categories in Human Ventral Temporal Cortex

The present functional magnetic resonance imaging study provides direct evidence on visual object-category formation in the human brain. Although brain imaging has demonstrated object-category specific representations in the occipitotemporal cortex, the crucial question of how the brain acquires this knowledge has remained unresolved. We designed a stimulus set consisting of six highly similar bird types that can hardly be distinguished without training. All bird types were morphed with one another to create different exemplars of each category. After visual training, fMRI showed that responses in the right fusiform gyrus were larger for bird types for which a discrete category-boundary was established as compared with not-trained bird types. Importantly, compared with not-trained bird types, right fusiform responses were smaller for visually similar birds to which subjects were exposed during training but for which no category-boundary was learned. These data provide evidence for experience-induced shaping of occipitotemporal responses that are involved in category learning in the human brain