A mathematical and computational review of Hartree-Fock SCF methods in Quantum Chemistry

We present here a review of the fundamental topics of Hartree-Fock theory in Quantum Chemistry. From the molecular Hamiltonian, using and discussing the Born-Oppenheimer approximation, we arrive to the Hartree and Hartree-Fock equations for the electronic problem. Special emphasis is placed in the most relevant mathematical aspects of the theoretical derivation of the final equations, as well as in the results regarding the existence and uniqueness of their solutions. All Hartree-Fock versions with different spin restrictions are systematically extracted from the general case, thus providing a unifying framework. Then, the discretization of the one-electron orbitals space is reviewed and the Roothaan-Hall formalism introduced. This leads to a exposition of the basic underlying concepts related to the construction and selection of Gaussian basis sets, focusing in algorithmic efficiency issues. Finally, we close the review with a section in which the most relevant modern developments (specially those related to the design of linear-scaling methods) are commented and linked to the issues discussed. The whole work is intentionally introductory and rather self-contained, so that it may be useful for non experts that aim to use quantum chemical methods in interdisciplinary applications. Moreover, much material that is found scattered in the literature has been put together here to facilitate comprehension and to serve as a handy reference.Comment: 64 pages, 3 figures, tMPH2e.cls style file, doublesp, mathbbol and subeqn package

Financial fragmentation and SMEs’ access to finance

This paper focuses on the impact of financial fragmentation on small and medium enterprises (SMEs)’ access to finance. We combine country-level data on financial fragmentation and the ECB’s SAFE (Survey on the Access to Finance of Enterprises) data for 12 European Union (EU) countries over 2009-2016. Our findings indicate that an increase in financial fragmentation not only raises the probability of all firms to be rationed but also to be charged higher loan rates; in addition, it increases the likelihood of borrower discouragement and it impairs firms’ perceptions of the future availability of bank funds. Less creditworthy firms are even more likely to become credit rationed, suggesting a flight to quality effect in lending. However, our study also documents a potential adverse effect of increasing bank market power resulting from greater integration. This suggests that financial integration could impair firms’ financing, if not accompanied by policy initiatives aimed at maintaining an optimal level of competition in the banking sector

Leptin Administration Favors Muscle Mass Accretion by Decreasing FoxO3a and Increasing PGC-1α in ob/ob Mice

Absence of leptin has been associated with reduced skeletal muscle mass in leptin-deficient ob/ob mice. The aim of our study was to examine the effect of leptin on the catabolic and anabolic pathways regulating muscle mass. Gastrocnemius, extensor digitorum longus and soleus muscle mass as well as fiber size were significantly lower in ob/ob mice compared to wild type littermates, being significantly increased by leptin administration (P<0.001). This effect was associated with an inactivation of the muscle atrophy-related transcription factor forkhead box class O3 (FoxO3a) (P<0.05), and with a decrease in the protein expression levels of the E3 ubiquitin-ligases muscle atrophy F-box (MAFbx) (P<0.05) and muscle RING finger 1 (MuRF1) (P<0.05). Moreover, leptin increased (P<0.01) protein expression levels of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), a regulator of muscle fiber type, and decreased (P<0.05) myostatin protein, a negative regulator of muscle growth. Leptin administration also activated (P<0.01) the regulators of cell cycle progression proliferating cell nuclear antigen (PCNA) and cyclin D1, and increased (P<0.01) myofibrillar protein troponin T. The present study provides evidence that leptin treatment may increase muscle mass of ob/ob mice by inhibiting myofibrillar protein degradation as well as enhancing muscle cell proliferation

Human malarial disease: a consequence of inflammatory cytokine release

Malaria causes an acute systemic human disease that bears many similarities, both clinically and mechanistically, to those caused by bacteria, rickettsia, and viruses. Over the past few decades, a literature has emerged that argues for most of the pathology seen in all of these infectious diseases being explained by activation of the inflammatory system, with the balance between the pro and anti-inflammatory cytokines being tipped towards the onset of systemic inflammation. Although not often expressed in energy terms, there is, when reduced to biochemical essentials, wide agreement that infection with falciparum malaria is often fatal because mitochondria are unable to generate enough ATP to maintain normal cellular function. Most, however, would contend that this largely occurs because sequestered parasitized red cells prevent sufficient oxygen getting to where it is needed. This review considers the evidence that an equally or more important way ATP deficency arises in malaria, as well as these other infectious diseases, is an inability of mitochondria, through the effects of inflammatory cytokines on their function, to utilise available oxygen. This activity of these cytokines, plus their capacity to control the pathways through which oxygen supply to mitochondria are restricted (particularly through directing sequestration and driving anaemia), combine to make falciparum malaria primarily an inflammatory cytokine-driven disease

Social Stories™ to alleviate challenging behaviour and social difficulties exhibited by children with autism spectrum disorder in mainstream schools : design of a manualised training toolkit and feasibility study for a cluster randomised controlled trial with nested qualitative and cost-effectiveness components

BACKGROUND: A Social Story™ (Carol Gray) is a child-friendly intervention that is used to give children with autism spectrum disorders (ASDs) social information in situations where they have social difficulties. Limited evidence mainly using single-case designs suggests that they can reduce anxiety and challenging behaviour. OBJECTIVES: The objectives were to conduct a systematic review, use this to develop a manualised intervention and run a feasibility trial to inform a fully powered randomised controlled trial (RCT) on their clinical effectiveness and cost-effectiveness in schools. DESIGN: This is a three-stage study following the Medical Research Council framework for complex interventions. Specifically, it involved a theoretical phase, a qualitative stage and a feasibility trial stage. SETTING: Qualitative interviews and focus groups took place in Child and Adolescent Mental Health Service and primary care settings. The feasibility study took place in 37 local mainstream schools. PARTICIPANTS: Fifty children (aged 5-15 years) in mainstream school settings with a diagnosis of ASD were entered into the trial. For each child, an associated teacher and parent was also recruited. INTERVENTIONS: The intervention was a goal-setting session followed by a manualised toolkit (including a training session) for creating Social Stories™ for use with school-aged children. The comparator treatment was a goal-setting session followed by an attention control. Both arms received treatment as usual. MAIN OUTCOME MEASURES: Outcomes tested as part of the feasibility study included child- and proxy-completed questionnaires for mental health, quality of life and goal-based outcome measures. Adults additionally completed behaviour diaries and the parental stress index. RESULTS: The review found that the research into social stories is predominantly based in the USA, carried out in under-12-year-olds and using single-case designs. Most studies either did not follow established Social Story criteria or did not report if they did. The assessment of effectiveness presents a largely positive picture but is limited by methodological issues. There were no adequate RCTs and insufficient information to assess a number of important sources of potential bias in most studies. A manualised intervention was produced using an iterative process between user focus groups and a writing team, and assessed in the feasibility study. All 50 participant groups were recruited within the study time frame. Two outcome measures, the Social Responsiveness Scale-2 and the custom-made goal-based measure, showed high levels of completion rates and appeared to be capturing social and behaviour skills targeted by the use of Social Stories. Detailed recommendations for a full trial are provided. LIMITATIONS: Blinding of participants was not feasible. Treatment fidelity was not assessed because of low levels of story return rates. CONCLUSIONS: The study showed that a fully powered RCT is feasible with an extended geographical footprint. A large amount of data and information has helped to inform the design of this RCT, which will be the subject of a future research grant application. Future work could focus on developing an appropriate blinded outcome measure for this population. STUDY REGISTRATION: This study is registered as PROSPERO CRD42011001440. TRIAL REGISTRATION: Current Controlled Trials ISRCTN96286707. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 6. See the NIHR Journals Library website for further project information