Curvature-processing network in macaque visual cortex

Our visual environment abounds with curved features. Thus, the goal of understanding visual processing should include the processing of curved features. Using functional magnetic resonance imaging in behaving monkeys, we demonstrated a network of cortical areas selective for the processing of curved features. This network includes three distinct hierarchically organized regions within the ventral visual pathway: a posterior curvature-biased patch (PCP) located in the near-foveal representation of dorsal V4, a middle curvature-biased patch (MCP) located on the ventral lip of the posterior superior temporal sulcus (STS) in area TEO, and an anterior curvature-biased patch (ACP) located just below the STS in anterior area TE. Our results further indicate that the processing of curvature becomes increasingly complex from PCP to ACP. The proximity of the curvature-processing network to the well-known face-processing network suggests a possible functional link between them.Decades of research have focused on understanding visual feature processing, particularly along the ventral visual pathway. Such studies have shown that neurons in lower-order visual areas (e.g., V1) respond strongly to simple oriented contours (1), whereas neurons in higher-order visual areas (e.g., inferior temporal cortex) respond selectively to more complex image features and/or visual categories (2–4), in ways that are not yet fully understood. To link these extremes in visual information processing, many studies have aimed to clarify the optimal “trigger” features at intermediate levels of the visual cortical hierarchy.Among these features, stimulus curvature has not been well studied. This is surprising because, strictly, all lines are curved to some extent, except for the single exception of a perfectly straight line. This ubiquity of curved shapes also extends to 3D surfaces (5). In nature, where much of our visual system presumably evolved, perfectly flat surfaces are rare. Even the flattest of natural features (e.g., oceans, sandy beaches) are often curved to some extent, due to wind, water motion, and even the curvature of the earth. Thus, it is important to understand curvature processing to fully unravel the steps in cortical visual processing.Among the few studies to test single neuron responses to curvature per se, Gallant et al. (6, 7) reported that a significant percentage of neurons in macaque cortical area V4 is selective for curved stimuli. Intriguingly, these authors also noted that neurons preferring curved patterns were often anatomically clustered together. Subsequently, Pasupathy and Connor (8–10) demonstrated that neurons in the parafoveal representation of dorsal V4 respond robustly to the curvature component of complex shapes. To our knowledge, there have been no systematic studies of curvature at levels below V4 in macaques.Intriguingly, some evidence suggests that the processing of curvature may interact selectively with the processing of faces. For instance, perceptual deficits in face recognition (prosopagnosia) are sometimes associated with deficits in curvature discrimination (11). In addition, some neurons in face-selective regions of the temporal lobe also respond to rounded nonface objects (12, 13). A human functional magnetic resonance imaging (fMRI) study (14) reported that a concentrically curved grating produced a larger response in the fusiform face-selective area (FFA) (15, 16), compared with an otherwise identical linear grating.Here, we tested for a cortical specialization of curvature processing, using fMRI in fixating macaque monkeys. Given the previous single-unit studies (6–10), we expected that curved stimulus features would activate V4, either in specific patches or distributed throughout the area. The present fMRI approach also allowed us to test whether curvature processing is confined to V4, or whether it extends into additional brain regions. If specialized areas for curvature processing were identified, we could then ask whether they might be topographically linked with face-selective regions. Such an arrangement would shorten the mean axonal length between curvature- and face-processing regions, if these regions were functionally related.     

Diagnostic test accuracy of magnetic resonance imaging and ultrasound for detecting bone erosion in patients with rheumatoid arthritis

Clinical Rheumatology - To evaluate and compare the diagnostic test accuracy of magnetic resonance imaging (MRI) and ultrasound (US) for bone erosion in rheumatoid arthritis (RA) patients for a...     

CDK12抑制剂在卵巢癌治疗中的研究进展

卵巢癌是死亡率最高的妇科肿瘤,其主要亚型高级浆液性卵巢癌的标准治疗模式效果欠佳,目前尚缺乏有效的临床治疗手段。细胞周期蛋白依赖性激酶（cyclin-dependent kinase, CDK）12作为CDKs中的一员,在调节基因转录、RNA剪接和DNA损伤修复等多种细胞进程中发挥重要作用。已有研究发现多种卵巢癌中存在CDK12基因突变,这些都提示了CDK12可作为潜在的治疗靶点。作者在阐述CDK12作用机制的基础上,介绍目前已发现的能够选择性抑制CDK12的试剂,并探讨CDK12抑制剂在多种类型卵巢癌中的治疗进展。     

Oral polio vaccine response in breast fed infants with malnutrition and diarrhea

Oral vaccines for polio (OPV) and rotavirus are less effective in children in the developing world. The reasons for this are not well understood. We tested for risk factors for poor response to OPV in infants from an urban slum of Dhaka, Bangladesh. Diminished serum neutralizing response to OPV, but not failure of intramuscularly administered vaccines, was associated with malnutrition, diarrhea, and shorter breastfeeding duration. Children with malnutrition (WAZ <−2) had significantly lower OPV 3 titers (p = 0.029). Children who had 2 or more diarrhea episodes during the 1st months of life were more than twice as likely to experience OPV failure as those who had 1 diarrhea episode or no diarrhea (p = 0.0245). In contrast, each additional month in exclusive breastfeeding was associated with an increase in OPV 3 titer by 0.41 (p = 0.0072) and 0.16 (p = 0.0065) at the 25th and 50th percentiles of OPV 3 titers respectively. These data are consistent with a defect in induction of immunity in the gut for OPV but not parenteral vaccines, a defect that may be amenable to intervention in part via promotion of exclusive breastfeeding.     

鞍山市铁东区公共场所使用化妆品存在的主要卫生问题及对策

目的了解鞍山市铁东区公共场所使用化妆品卫生问题,保障使用者身体健康。方法对2013年度鞍山市铁东区卫生防疫站辖区内监管的公共场所随机抽检化妆品,对公共场所使用化妆品单位数及比例,化妆品标签标识卫生问题等进行描述。结果住宿业化妆品使用情况为56%,其他三种场所100%使用。化妆品标签标识检查住宿业合格率最低,仅为50%。国产特殊用途化妆品持有效证件率仅为65%,普通的仅为62%。标签标识问题突出,进货渠道复杂。化妆品抽检合格率低。结论公共场所的化妆品卫生质量令人担忧。     

鞍山市铁东区公共场所卫生基层问题及解决建议

笔者作为基层卫生监督工作人员经过十多年的公共场所卫生监督工作,通过对鞍山市铁东区公共场所卫生监督情况进行分析。发现当前存在许多公共场所卫生监督执法困难和难题,主要表现为卫生监督队伍薄弱,新兴公共场所剧增,公共场所执法依据不确定性（无法可依）等问题。笔者提出相应的解决建议,应转变卫生监督观念,提高监督管理质量。     

Risk factors for acute kidney injury (AKI) in infants with melamine-associated urolithiasis and follow-up: a multi-center retrospective analysis

An epidemic of urinary tract stones was noted among infants in China, 2008. This event was believed to be associated with consumption melamine-contaminated powdered formula. The patients with symptoms and clinical manifests had already been analyzed in our previous studies. In this study, our aim is to investigate the risk factors of melamine-associated acute kidney injury (AKI) and the potential relationship toward children growth in our five years follow-up. A total of 619 infants with melamine-associated urolithiasis were admitted into 20 different hospitals in the Gansu province, China. All clinical data were divided into AKI and control groups according to the occurrence of AKI. Univariate and multivariate analyses were performed with a logistic regression model to assess the independent risk factors of AKI. Logistic regression analysis revealed that the odds ratio (OR) of AKI was 19.62 in the group of infants who consumed Sanlu® milk powdered infant milk formula. A higher prevalence of AKI was observed in infants age of 6–11 months (OR: 9.59, p?p?p?相似文献