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Previous studies have reported that patient with schizophrenia have preserved hedonic capacity, but impaired ability to anticipate future reward (anticipatory anhedonia) that, according to some authors, may underlie other aspects of negative symptoms, such as avolition.
The aim of our study was to demonstrate an impairment of reward anticipation in patients with deficit schizophrenia (DS), characterized by primary and persistent negative symptoms, but not in those with non-deficit schizophrenia (NDS) with respect to healthy controls (HC), by means of functional magnetic resonance imaging (fMRI).
fMRI was recorded during the execution of the ’Monetary Incentive Delay’ task in 11 patients with DS, 23 patients with NDS and 23 HC, during the anticipation of five different outcomes, small (SR) or large (LR) reward, small (SP) or large (LP) punishment or no-outcome (NO).
The ventral striatum response to reward anticipation was preserved in subjects with schizophrenia. Only patients with DS, compared with HC, showed a significant reduction in the left caudate during the anticipation of reward. The reduced activity of the caudate correlated with the scores for avolition but not for anhedonia.
Our preliminary data suggest an involvement of the caudate in the abnormal processing of reward stimuli in patients with DS and show that avolition and anhedonia are subtended by different functional abnormalities.
D-aspartate (D-Asp) is an atypical amino acid that binds to and activates NMDARs. D-Asp occurs abundantly in the embryonic brain of mammals and rapidly decreases after birth, due to the activity of the enzyme D-Aspartate Oxidase (DDO). The agonistic activity of D-Asp on NMDARs and its neurodevelopmental occurrence make this D-amino acid a potential mediator for NMDAR-related alterations observed in schizophrenia. Consistently, substantial reduction of D-Asp was observed in post-mortem schizophrenia brains.
We evaluated the potential contribution of D-Asp as neurodevelopmental modulator of brain circuits and behaviors relevant to schizophrenia.
We analyzed DDO mRNA expression in the post-mortem prefrontal cortex of schizophrenic patients. Moreover, we treated knockout mice for Ddo gene (Ddo-/-) with the NMDAR antagonist phencyclidine to evaluate their schizophrenia-relevant behaviors and circuits. Finally, we assessed cortico-hippocampal connectivity of these mice.
DDO mRNA detection was performed by quantitative PCR. Phencyclidine-induced schizophrenia-like behaviours were assessed through motor activity and prepulse inhibition paradigms. Resting-state and pharmacological fMRI were used to evaluate functional circuits and connectivity.
DDO mRNA expression is increased in frontal samples of schizophrenic patients. In mice, the absence of Ddo gene produces a significant reduction in phencyclidine-induced motor hyper-activity and prepulse inhibition deficit. Furthermore, increased levels of D-Asp in Ddo-/- animals significantly inhibit functional circuits activated by phencyclidine, and affect the development of cortico-hippocampal connectivity networks potentially involved in schizophrenia.
Our data suggest that D-Asp, through the regulation exerted by DDO, may have a role in the pathophysiology of schizophrenia.
Using the coefficient of variations for heights, this paper examines the evolution of net nutrition inequality in Argentina from 1875 to 1950. It uses various samples of recruits and soldiers, previously gathered by the author. Evidence points to two important findings: (a) export-led growth led to stable or declining net-nutrition inequality; while import-substituting industrialisation generated significant net nutrition inequality; and (b) the highest levels of inequality in net nutrition took place during this latter phase in large urban, industrialised areas.
To determine the typical microbial bioburden (overall bacterial and multidrug-resistant organisms [MDROs]) on high-touch healthcare environmental surfaces after routine or terminal cleaning.
Prospective 2.5-year microbiological survey of large surface areas (>1,000 cm2).
MDRO contact-precaution rooms from 9 acute-care hospitals and 2 long-term care facilities in 4 states.
Samples from 166 rooms (113 routine cleaned and 53 terminal cleaned rooms).
Using a standard sponge-wipe sampling protocol, 2 composite samples were collected from each room; a third sample was collected from each Clostridium difficile room. Composite 1 included the TV remote, telephone, call button, and bed rails. Composite 2 included the room door handle, IV pole, and overbed table. Composite 3 included toileting surfaces. Total bacteria and MDROs (ie, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci [VRE], Acinetobacter baumannii, Klebsiella pneumoniae, and C. difficile) were quantified, confirmed, and tested for drug resistance.
The mean microbial bioburden and range from routine cleaned room composites were higher (2,700 colony-forming units [CFU]/100 cm2; ≤1–130,000 CFU/100 cm2) than from terminal cleaned room composites (353 CFU/100 cm2; ≤1–4,300 CFU/100 cm2). MDROs were recovered from 34% of routine cleaned room composites (range ≤1–13,000 CFU/100 cm2) and 17% of terminal cleaned room composites (≤1–524 CFU/100 cm2). MDROs were recovered from 40% of rooms; VRE was the most common (19%).
This multicenter bioburden summary provides a first step to determining microbial bioburden on healthcare surfaces, which may help provide a basis for developing standards to evaluate cleaning and disinfection as well as a framework for studies using an evidentiary hierarchy for environmental infection control.
The neurobiological underpinnings of avolition in schizophrenia remain unclear. Most brain imaging research has focused on reward prediction deficit and on ventral striatum dysfunction, but findings are not consistent. In the light of accumulating evidence that both ventral striatum and dorsal caudate play a key role in motivation, we investigated ventral striatum and dorsal caudate activation during processing of reward or loss in patients with schizophrenia.
We used functional magnetic resonance imaging to study brain activation during a Monetary Incentive Delay task in patients with schizophrenia, treated with second-generation antipsychotics only, and in healthy controls (HC). We also assessed the relationships of ventral striatum and dorsal caudate activation with measures of hedonic experience and motivation.
The whole patient group had lower motivation but comparable hedonic experience and striatal activation than HC. Patients with high avolition scores showed lower dorsal caudate activation than both HC and patients with low avolition scores. A lower dorsal caudate activation was also observed in patients with deficit schizophrenia compared to HC and patients with non-deficit schizophrenia. Dorsal caudate activity during reward anticipation was significantly associated with avolition, but not with anhedonia in the patient group.
These findings suggest that avolition in schizophrenia is linked to dorsal caudate hypoactivation.
The essay examines the conditions of book accumulation in two places in the world economy, California and Peru, through the narratives left by book collector Hubert Bancroft and librarian and historian Jorge Basadre. A reading of these reveals the complex interrelations between socioeconomic development and cultural accumulation. In California, Bancroft turned his fortune accumulated through business into a unique book collection and this, in turn, was placed at the service of a “factory of history” that produced a multivolume “History of the Pacific States of North America.” In the Peruvian case, after a fire destroyed most of the collections of the National Library of Lima, historian Basadre directed an effort of reconstruction that led him to reflect upon the state's neglect of cultural patrimony, popular disdain for high culture, and Peru's long tradition of exporting books and documents to foreign collectors and libraries. Basadre's reflections speak of the position of a peripheral intellectual within a context of underdevelopment. I examine the centripetal logic of book accumulation and call for further engagement with this neglected side of cultural history.
We investigated a cluster of cases of bloodstream infection (BSI) due to the mold Phialemonium at a hemodialysis center in Illinois and conducted a cohort study to identify risk factors.
Environmental assessment and cohort study.
A hemodialysis center in a tertiary care hospital.
A case patient was defined as a person who underwent dialysis at the center and had a blood sample that tested positive for Phialemonium curvatum on culture. We reviewed microbiology and medical records and tested water, surface, and dialysate samples by culture. Molds isolated from environmental and clinical specimens were identified by their morphological features and confirmed by sequencing DNA.
We identified 2 case patients with BSI due to P. curvatum. Both became febrile and hypotensive while undergoing dialysis on the same machine at the same treatment station, although on different days. Dialysis machines were equipped with waste handling option ports that are used to discard dialyzer priming fluid. We isolated P. curvatum from the product water (ie, water used for dialysis purposes) at 2 of 19 treatment stations, one of which was the implicated station.
The source of P. curvatum was likely the water distribution system. To our knowledge, this is the first report of patients acquiring a mold BSI from contaminated product water. The route of exposure in these cases of BSI due to P. curvatum may be related to the malfunction and improper maintenance of the waste handling option ports. Waste handling option ports have been previously implicated as the source of bacterial BSI due to the backflow of waste fluid into a patient's blood line. No additional cases of infection were noted after remediation of the water distribution system and after discontinuing use of waste handling option ports at the facility.
We present the realization of hybrid silicon core/silicon nitride shell nanodots by Low Pressure Chemical Vapor Deposition (LPCVD) and their application as floating gate in Non Volatile Memory (NVM) devices. The LPCVD process includes three steps: nucleation using SiH4, selective growth of the silicon nuclei using SiH2Cl2 and finally selective growth of silicon nitride using a mixture of SiH2Cl2 and NH3 around the silicon dot. The two first steps have already been described in literature. We will therefore focus on the selective growth of a nitride layer on silicon dots. Morphological characterization using Scanning Electron Microscopy (SEM) allows control over dots size – 5 to 10nm – and density – up to 1E12/cm2. High Resolution Transmission Electron Microscopy (HRTEM) shows a crystalline silicon core and an outer shell of amorphous silicon nitride. Energy Filtered TEM pictures confirm that the nitride layer is deposited only around the silicon dots and not on the oxide. Oxidation resistance of the silicon nitride shell is also investigated. A 2nm thick silicon nitride layer is an efficient barrier to an oxidation at 800°C in dry oxygen for 5 minutes. We thus have a very thin high quality stoechiometric nitride layer. Such a high quality nitride film can only be achieved using in-situ deposition i.e. on an oxide-free silicon surface. Finally, hybrid Si/SiN nanodots are integrated in a single memory cell with high-K interpoly dielectric. Electrical results show large threshold voltage shift of 6V. The use of silicon nitride shells on the silicon dots has therefore two main advantages: it provides both oxidation resistance and charge storage enhancement.
This essay presents recent estimates of average heights for different regions of Argentina during the period 1850–1950. This evidence, taken from registers of prisoners and military recruits, serves to question some traditional views of Argentine economic growth based on income and wage data. The essay suggests that the era of liberal progress resulted in less welfare among the lower classes than is usually assumed. A similar situation occurred during the agrarian-export growth of the first decade of the 20th century. In contrast, the period known as the «great delay» wit- nessed notable improvements in biological welfare, particularly during the 1930s. In addition, height estimates indicate that during WWII and the first Peronist administrations there was a nutritional setback in the Buenos Aires industrial belt. Data on the provincial distribution of heights for the 1920s show an important degree of regional inequality.
The paper reports on the amorphization kinetics of chalcogenides ternary alloy induced by Ar or Sb ion irradiation. The reflectivity data, obtained “in situ” during irradiation, allow a description of the amorphization process in terms of a threshold fluence. The results demonstrate that amorphization is caused by the elastic collisions of the projectiles with target nuclei. The influence of the ion mass and energy, of the target temperature in the amorphization is also reported.