Noninvasive Transcranial Direct Current Stimulation Over the Left Prefrontal Cortex Facilitates Cognitive Flexibility in Tool Use

This is an Accepted Manuscript of an article published by Taylor & Francis in Cognitive Neuroscience on 2013-06-1, available online: http://www.tandfonline.com/10.1080/17588928.2013.768221.Recent neuroscience evidence suggests that some higher-order tasks might benefit from a reduction in sensory filtering associated with low levels of cognitive control. Guided by neuroimaging findings, we hypothesized that cathodal (inhibitory) transcranial direct current stimulation (tDCS) will facilitate performance in a flexible use generation task. Participants saw pictures of artifacts and generated aloud either the object’s common use or an uncommon use for it, while receiving cathodal tDCS (1.5 mA) either over left or right PFC, or sham stimulation. A forward digit span task served as a negative control for potential general effects of stimulation. Analysis of voice-onset reaction times and number of responses generated showed significant facilitative effects of left PFC stimulation for the uncommon, but not the common use generation task and no effects of stimulation on the control task. The results support the hypothesis that certain tasks may benefit from a state of diminished cognitive control

Single molecule tracking fluorescence microscopy in mitochondria reveals highly dynamic but confined movement of Tom40

Tom40 is an integral protein of the mitochondrial outer membrane, which as the central component of the Translocase of the Outer Membrane (TOM) complex forms a channel for protein import. We characterize the diffusion properties of individual Tom40 molecules fused to the photoconvertable fluorescent protein Dendra2 with millisecond temporal resolution. By imaging individual Tom40 molecules in intact isolated yeast mitochondria using photoactivated localization microscopy with sub-diffraction limited spatial precision, we demonstrate that Tom40 movement in the outer mitochondrial membrane is highly dynamic but confined in nature, suggesting anchoring of the TOM complex as a whole

Depolarization-Evoked Secretion Requires Two Vicinal Transmembrane Cysteines of Syntaxin 1A

BACKGROUND: The interactions of the voltage-gated Ca(2+) channel (VGCC) with syntaxin 1A (Sx 1A), Synaptosome-associated protein of 25 kD (SNAP-25), and synaptotagmin, couple electrical excitation to evoked secretion. Two vicinal Cys residues, Cys 271 and Cys 272 in the Sx 1A transmembrane domain, are highly conserved and participate in modulating channel kinetics. Each of the Sx1A Cys mutants, differently modify the kinetics of Cav1.2, and neuronal Cav2.2 calcium channel. METHODOLOGY/PRINCIPLE FINDINGS: We examined the effects of various Sx1A Cys mutants and the syntaxin isoforms 2, 3, and 4 each of which lack vicinal Cys residues, on evoked secretion, monitoring capacitance transients in a functional release assay. Membrane capacitance in Xenopus oocytes co-expressing Cav1.2, Sx1A, SNAP-25 and synaptotagmin, which is Bot C- and Bot A-sensitive, was elicited by a double 500 ms depolarizing pulse to 0 mV. The evoked-release was obliterated when a single Cys Sx1A mutant or either one of the Sx isoforms were substituted for Sx 1A, demonstrating the essential role of vicinal Cys residues in the depolarization mediated process. Protein expression and confocal imaging established the level of the mutated proteins in the cell and their targeting to the plasma membrane. CONCLUSIONS/SIGNIFICANCE: We propose a model whereby the two adjacent transmembranal Cys residues of Sx 1A, lash two calcium channels. Consistent with the necessity of a minimal fusion complex termed the excitosome, each Sx1A is in a complex with SNAP-25, Syt1, and the Ca(2+) channel. A Hill coefficient >2 imply that at least three excitosome complexes are required for generating a secreting hetero-oligomer protein complex. This working model suggests that a fusion pore that opens during membrane depolarization could be lined by alternating transmembrane segments of Sx1A and VGCC. The functional coupling of distinct amino acids of Sx 1A with VGCC appears to be essential for depolarization-evoked secretion

Effect of blood glucose level on standardized uptake value (SUV) in F-18- FDG PET-scan : a systematic review and meta-analysis of 20,807 individual SUV measurements

Objectives To evaluate the effect of pre-scan blood glucose levels (BGL) on standardized uptake value (SUV) in F-18-FDG-PET scan. Methods A literature review was performed in the MEDLINE, Embase, and Cochrane library databases. Multivariate regression analysis was performed on individual datum to investigate the correlation of BGL with SUVmax and SUVmean adjusting for sex, age, body mass index (BMI), diabetes mellitus diagnosis, F-18-FDG injected dose, and time interval. The ANOVA test was done to evaluate differences in SUVmax or SUVmean among five different BGL groups (200 mg/dl). Results Individual data for a total of 20,807 SUVmax and SUVmean measurements from 29 studies with 8380 patients was included in the analysis. Increased BGL is significantly correlated with decreased SUVmax and SUVmean in brain (p <0.001, p <0.001,) and muscle (p <0.001, p <0.001) and increased SUVmax and SUVmean in liver (p = 0.001, p = 0004) and blood pool (p=0.008, p200 mg/dl had significantly lower SUVmax. Conclusion If BGL is lower than 200mg/dl no interventions are needed for lowering BGL, unless the liver is the organ of interest. Future studies are needed to evaluate sensitivity and specificity of FDG-PET scan in diagnosis of malignant lesions in hyperglycemia.Peer reviewe

Arabic Toponymy around Ashkelon: The Village of Hamama as a Case Study

Arabic Toponymy around Ashkelon: The Village of Hamama as a Case Study The village of Hamama, situated between the cities of Ashdod and Ashkelon, was the second largest village, in both its territory and the number of its inhabitants, in the Gaza sub-district during the British Mandate period. The article surveys and discusses the Arab toponymy of Hamama, as part of the broader corpus of Palestinian rural toponymy in Ashkelon’s hinterland before 1948. The article reviews the scholarly trends in the study of Arabic toponymy. In light of the toponyms, the article traces the social, geographical and historical characteristics of village toponyms, and assesses their connection to its natural and man-made geographies. Underlying the Late Ottoman and British Mandate corpus, is a limited stratum of pre-Ottoman village names. To this pre-exiting stratum, new toponyms were added, referring in cases to families living in or around the village. The great importance of land as the main means of production in Hamama’s agrarian society, is manifested by the many toponyms relating to the soil and its characteristics. Many names refer to various types of agricultural plots (gardens, orchards, vineyards, orchards and mawasi plots of land irrigated from shallow wells dug in sand dunes along the coast), in addition to the phenomenon of coastal wetlands (birak). Toponyms provide external evidence of the names of the village families, corroborating names known from the ethnographic literature. Furthermore, it reflects Hamama’s sacred geography, e.g. village shrines and their endowments. Finally, the article briefly discusses the ways in which new place names were derived from existin

The Study of the Arab Countryside throughout the Generations: The Arab Settlement in the Sharon Region as a Case Study

This article seeks to explore past and present trends in the study of the Palestinian countryside, as reflected in Israeli and Arab-Palestinian scholarship about the Plain of Sharon—a key section of Palestine’s coastal plain. The article presents a detailed exposition of the different schools of thought, and by establishing the drawbacks of each school, it argues the need for an integrative approach to the subject and sources at hand. Scholars must therefore consider all the relevant primary sources and secondary literature. Furthermore, they should discuss their object of inquiry from both the perspective of the village and that of the region as a whole.Before 1948, Palestinians lived in a predominantly rural society. Therefore, a systematic treatment of the Palestinian countryside is vital for conducting any thorough discussion of the country’s history. Indeed, the social, economic, and demographic history of the Palestinian countryside during the Ottoman and British Mandate periods has received a significant scientific attention. Historians, archaeologists, anthropologists, sociologists, economists, demographers and material-culture researchers all long participated in a lively scholarly discourse in English, Hebrew, Arabic, Turkish, and more, mainly European languages. This attention reflects not only an interest in the ongoing Palestinian-Zionist conflict, but—more importantly—the accelerated pace of digitization of archival materials. The digital revolution, with the internet and social networks, removed previous political, geographical and financial barriers to scholarly exchange, and provided direct access to primary sources in various languages and from a wide variety of archival collections in Israel/Palestine and abroad.Jewish ethnographic accounts of the Palestinian countryside were inspired by everyday contacts with Palestinian society during the British Mandate period and influenced by available Western studies. Later, Zionist intelligence officers, like Ezra Danin, Tuvia Ashkenazi, and Ya‘akov Shimoni, documented land ownership patterns, structures of power and high politics for the purposes of the Jewish Yishuv. Following the establishment of the State of Israel, Israeli geographers like David Amiran, Yehuda Karmon and Gidon Golani of the Hebrew University of Jerusalem, working in the service of the Israeli state planning apparatuses, presented a spatial perspective of the ‘Arab Village’. They utilized geographical tools and also based their work on field work and official statistics. Early Israeli scholarship about the ‘Arab village’ (Heb. Ha-kfar ha-‘Aravi) reflected Jewish perceptions of the Arab-Palestinian ‘Other’. More specifically, it embodied the ways in which Israeli scholars, most of whom of European origin, conceived the ‘Arab Village’ in light of general Orientalist perceptions of the East, and specific Zionist national preoccupations. Their studies of the ‘Arab village’ were motivated by the need to understand, to contain and to control Israel’s Arab citizenry. With few exceptions, early Jewish scholars like Karmon and Amiran regarded the ‘Arab village’ as an Oriental, traditional, backward, unorganized settlement form, constrained by the limitations of the environment. Jewish settlements, on the other hand, were hailed as a Western, modern, advanced, planned and prosperous settlement form, which overcame nature for the benefit of humanity.This dichotomy of settlement forms manifested Jewish ethnocentric, temporal and spatial conceptions about the Land of Israel (Heb. Eretz Israel), encoded in Zionist doctrine and praxis. Zionist scholars, officials and educators, formulated, in scholarly terms, a ‘Theory of Settlement Decline.’ For them, the perceived miserable condition of the ‘Arab Village’ proved the decline of the Land of Israel after the exile of the Jewish People. The previous condition of the country could only be reversed, they argued, by the return of the chosen people to their ancestral home.This narrative served to marginalize and de-legitimize traditional Arab forms of settlement, as well as ownership, possession and use of land. More severely, it served Israeli functionaries as justification for the appropriation of vast swaths of privately-owned Arab-Palestinian land for exclusive Jewish use. The importance that Israel’s state apparatus and the security establishment attached to this legitimizing work is evident in the material support they extended to researchers who carried out these studies on their behalf. This trend has diminished since the 1970s, especially because of the more scientifically rigorous and less ideologicallyminded scholarship of a new generation of geographers, led by David Grossman of Bar Ilan University, and fellow colleagues from Tel Aviv University and the University of Haifa.Arab-Palestinian scholarship, for its part, embodies a national discourse whose aim is to secure, perpetuate and confirm the Palestinian Right of Return, and to highlight the Arab-Palestinian character of the land against Israeli attempts to ‘Judiaize’ it. Arab-Palestinian scholarship focuses mainly on the socio-cultural aspects of individual villages, and pays little attention to the geographical, or wider regional, dimensions. In the hundreds of ‘village books’ written since the 1940s, the claim of Palestinian historical continuity and autochthonous existence since Canaanite times stands in sharp contrast to the more recent reported origin of village families from other parts of the Levant.Since the 1980s, Sharif Kana‘ana’s team scholars from Bir Zeit University, followed by their colleagues from Al-Najah University in Nablus, made an indispensable contribution to the understanding of the history of the Palestinian countryside. They were the first to make extensive use of previously untapped local and Ottoman sources, including the oral accounts of village residents. Later, Arab Palestinian residents of Israel, educated in Israeli universities, made steps towards bridging the gap between Palestinian and Israeli scholarship. They utilized their linguistical proficiencies and access to archives on both sides to present a more rigorous account on the history of the Palestinian countryside than ever before. The main gap between Israeli and Arab-Palestinian scholarship is thus an ideological one, a state worsened by the often selective and non-exhaustive use of different corpora of sources. Researchers are now able to re-evaluate existing scholarship in light of the new data as well as insights gleaned from archaeology, ethnography, the history of the Ottoman Empire, the history of nomadic societies, oral history, cartography and digital mapping (GIS studies), as discussed in the article