Balancing the 2 Hemispheres in Simple Calculation: Evidence From Direct Cortical Electrostimulation

Published: 24 September 2016How do the parietal lobes contribute to simple calculation? Clinical and neuroimaging methods, which are based mainly on correlational evidence, have provided contrasting results so far. Here we used direct cortical electrostimulation during brain surgery to causally infer the role of the left and right parietal lobes in simple calculation. Stimulation provoked errors for addition and multiplication in different parietal areas on both hemispheres. Crucially, an innovative qualitative error analysis unveiled the functional contrast of the 2 parietal lobes. Right or left stimulation led to different types of substitution errors in multiplication, unveiling the function of the more active hemisphere. While inhibition of the left hemisphere led mainly to approximation errors, right hemisphere inhibition enhanced retrieval within a stored repertory. These results highlight the respective roles of each hemisphere in the network: rote retrieval of possible solutions by the left parietal areas and approximation to the correct solution by the right hemisphere. The bilateral orchestration between these functions guarantees precise calculation.This work was supported by the Italian Ministry of Health (grant RF-2009-1530973); by the University of Padua (Grant Progetto d’Ateneo CPDA131328 and Progetto strategico NEURAT) to C.S., and by the Spanish Ministry of Science and Innovation (grant PSI2014-53351) to E.S. and by financial assistance as a Severo Ochoa Center of Excellence SEV-2015-0490 to the BCBL (E.S.)

The impact of economic crises on communicable disease transmission and control: a systematic review of the evidence.

There is concern among public health professionals that the current economic downturn, initiated by the financial crisis that started in 2007, could precipitate the transmission of infectious diseases while also limiting capacity for control. Although studies have reviewed the potential effects of economic downturns on overall health, to our knowledge such an analysis has yet to be done focusing on infectious diseases. We performed a systematic literature review of studies examining changes in infectious disease burden subsequent to periods of crisis. The review identified 230 studies of which 37 met our inclusion criteria. Of these, 30 found evidence of worse infectious disease outcomes during recession, often resulting from higher rates of infectious contact under poorer living circumstances, worsened access to therapy, or poorer retention in treatment. The remaining studies found either reductions in infectious disease or no significant effect. Using the paradigm of the "SIR" (susceptible-infected-recovered) model of infectious disease transmission, we examined the implications of these findings for infectious disease transmission and control. Key susceptible groups include infants and the elderly. We identified certain high-risk groups, including migrants, homeless persons, and prison populations, as particularly vulnerable conduits of epidemics during situations of economic duress. We also observed that the long-term impacts of crises on infectious disease are not inevitable: considerable evidence suggests that the magnitude of effect depends critically on budgetary responses by governments. Like other emergencies and natural disasters, preparedness for financial crises should include consideration of consequences for communicable disease control

Tracking infectious diseases in a warming world.

Using infectious diseases sensitive to climate as indicators of climate change helps stimulate andinform public health response

Reproductive toxins and alligator abnormalities at Lake Apopka, Florida.

The alligator population at Lake Apopka in central Florida declined dramatically between 1980 and 1987. Endocrine-disrupting chemicals and specifically DDT metabolites have been implicated in the alligators' reproductive failure. The DDT metabolite hypothesis is based largely on the observation of elevated concentrations of p,p-DDE and p,p-DDD in alligator eggs obtained from Lake Apopka in 1984 and 1985. In the following commentary, we draw attention to two nematocides that are established reproductive toxins in humans, dibromochloropropane (DBCP) and ethylene dibromide (EDB), which could also have played a role in the reproductive failure observed in alligators from Lake Apopka in the early 1980s

Self-reported access to health care, communicable diseases, violence and perception of legal status among online transgender identifying sex workers in the UK.

OBJECTIVES: Transgender-identifying sex workers (TGISWs) are among the most vulnerable groups but are rarely the focus of health research. Here we evaluated perceived barriers to healthcare access, risky sexual behaviours and exposure to violence in the United Kingdom (UK), based on a survey of all workers on BirchPlace, the main transgender sex commerce website in the UK. STUDY DESIGN: The study design used in the study is an opt-in text-message 12-item questionnaire. METHODS: Telephone contacts were harvested from BirchPlace's website (n = 592 unique and active numbers). The questionnaire was distributed with Qualtrics software, resulting in 53 responses. RESULTS: Our survey revealed significant reported barriers to healthcare access, exposure to risky sexual behaviours and to physical violence. Many transgender sex workers reportedly did not receive a sexual screening, and 28% engaged in condomless penetrative sex within the preceding six months, and 68% engaged in condomless oral sex. 17% responded that they felt unable to access health care they believed medically necessary. Half of the participants suggested their quality of life would be improved by law reform. CONCLUSIONS: TGISWs report experiencing a high level of risky sexual behaviour, physical violence and inadequate healthcare access. Despite a National Health System, additional outreach may be needed to ensure access to services by this population.ECD

Mapping Climate Change Vulnerabilities to Infectious Diseases in Europe

Background: The incidence, outbreak frequency, and distribution of many infectious diseases are generally expected to change as a consequence of climate change, yet there is limited regional information available to guide decision making