Geography, Health Status, and Health Investments: An Analysis of Peru

The study examines the influence of natural geography on human health in Peru, a country that has performed rather poorly, in the Latin American context, in terms of reducing its infant and maternal mortality rates. We measured natural geography through rainfall, temperature, altitude, longitude, and latitude. We also analyzed the effect that natural geography may have on the effectiveness of government health investments. We find evidence that geography has an important and independent influence on the infant mortality rate (IMR) and the child malnutrition rate (CMNR). As latitude and longitude increase (i. e. , as one moves towards the southwest) the IMR drops. Also, higher levels of rainfall (as in the Jungle region), and higher latitudes increase the CMNR. Lower temperatures, such as those observed in the Mountain region, seem to cause higher rates of child malnutrition. Geography also appears to affect the effectiveness of government health care investments. As latitude increases towards the south, thereby reducing the IMR, health centers and posts see their effectiveness reduced. Likewise, as longitude increases towards the west, thus helping to reduce the IMR, government health centers and posts become less effective in curtailing infant mortality. These results point to a decreasing marginal productivity of government health care spending. Several variables other than geography also affect health status. For example, we find that an increase in the illiteracy rate from 10 percent to 50 percent would bring about an increase in the IMR from 40 to 75 deaths per 1,000 live births. Female illiteracy has an important influence on the IMR as well, with higher levels of illiteracy being associated with a higher IMR. A policy of increasing general and female education through public spending thus appears to be an effective way of improving infant and child health. The government of Peru has invested heavily in ambulatory facilities in areas of high IMR. These new investments may have had a positive impact on child health. However, whatever this impact, so far it appears to be mild, and not enough to overcome the low health status that led to these new investments in the first place. While endogeneity problems have kept us from measuring the effectiveness of public investments in ambulatory care infrastructure, we find that the number of doctors working in public facilities has a positive influence on child health and nutritional status. We are able to show through simulations how new public resources devoted to new facilities and doctors could be allocated among the provinces to reduce regional inequality in health status. Finally, we find that natural geography exacerbates inequality in health status, as do existing regional differences in the availability of public services, such as potable water, sewerage, electricity, and in education. Public investments aimed at reducing or eliminating such differences would help to improve equity in health status.

Sustaining the Internet with Hyperbolic Mapping

The Internet infrastructure is severely stressed. Rapidly growing overheads associated with the primary function of the Internet---routing information packets between any two computers in the world---cause concerns among Internet experts that the existing Internet routing architecture may not sustain even another decade. Here we present a method to map the Internet to a hyperbolic space. Guided with the constructed map, which we release with this paper, Internet routing exhibits scaling properties close to theoretically best possible, thus resolving serious scaling limitations that the Internet faces today. Besides this immediate practical viability, our network mapping method can provide a different perspective on the community structure in complex networks

Phage inducible islands in the gram-positive cocci

The SaPIs are a cohesive subfamily of extremely common phage-inducible chromosomal islands (PICIs) that reside quiescently at specific att sites in the staphylococcal chromosome and are induced by helper phages to excise and replicate. They are usually packaged in small capsids composed of phage virion proteins, giving rise to very high transfer frequencies, which they enhance by interfering with helper phage reproduction. As the SaPIs represent a highly successful biological strategy, with many natural Staphylococcus aureus strains containing two or more, we assumed that similar elements would be widespread in the Gram-positive cocci. On the basis of resemblance to the paradigmatic SaPI genome, we have readily identified large cohesive families of similar elements in the lactococci and pneumococci/streptococci plus a few such elements in Enterococcus faecalis. Based on extensive ortholog analyses, we found that the PICI elements in the four different genera all represent distinct but parallel lineages, suggesting that they represent convergent evolution towards a highly successful lifestyle. We have characterized in depth the enterococcal element, EfCIV583, and have shown that it very closely resembles the SaPIs in functionality as well as in genome organization, setting the stage for expansion of the study of elements of this type. In summary, our findings greatly broaden the PICI family to include elements from at least three genera of cocci

Bronchiectasis:Phenotyping a Complex Disease

Bronchiectasis is a long-neglected disease currently experiencing a surge in interest. It is a highly complex condition with numerous aetiologies, co-morbidities and a heterogeneous disease presentation and clinical course. The past few years have seen major advances in our understanding of the disease, primarily through large real-life cohort studies. The main outcomes of interest in bronchiectasis are symptoms, exacerbations, treatment response, disease progression and death. We are now more able to identify clearly the radiological, clinical, microbiological and inflammatory contributors to these outcomes. Over the past couple of years, multidimensional scoring systems such as the Bronchiectasis Severity Index have been introduced to predict disease severity and mortality. Although there are currently no licensed therapies for bronchiectasis, an increasing number of clinical trials are planned or ongoing. While this emerging evidence is awaited, bronchiectasis guidelines will continue to be informed largely by real-life evidence from observational studies and patient registries. Key developments in the bronchiectasis field include the establishment of international disease registries and characterisation of disease phenotypes using cluster analysis and biological data.</p

Thermal width and gluo-dissociation of quarkonium in pNRQCD

The thermal width of heavy-quarkonium bound states in a quark-gluon plasma has been recently derived in an effective field theory approach. Two phenomena contribute to the width: the Landau damping phenomenon and the break-up of a colour-singlet bound state into a colour-octet heavy quark-antiquark pair by absorption of a thermal gluon. In the paper, we investigate the relation between the singlet-to-octet thermal break-up and the so-called gluo-dissociation, a mechanism for quarkonium dissociation widely used in phenomenological approaches. The gluo-dissociation thermal width is obtained by convoluting the gluon thermal distribution with the cross section of a gluon and a 1S quarkonium state to a colour octet quark-antiquark state in vacuum, a cross section that at leading order, but neglecting colour-octet effects, was computed long ago by Bhanot and Peskin. We will, first, show that the effective field theory framework provides a natural derivation of the gluo-dissociation factorization formula at leading order, which is, indeed, the singlet-to-octet thermal break-up expression. Second, the singlet-to-octet thermal break-up expression will allow us to improve the Bhanot--Peskin cross section by including the contribution of the octet potential, which amounts to include final-state interactions between the heavy quark and antiquark. Finally, we will quantify the effects due to final-state interactions on the gluo-dissociation cross section and on the quarkonium thermal width.Comment: 17 pages, 6 figure

Classifying new anti-tuberculosis drugs: Rationale and future perspectives

The classification of anti-tuberculosis (TB) drugs is important as it helps the clinician to build an appropriate anti-TB regimen for multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB cases that do not fulfil the criteria for the shorter MDR-TB regimen. The World Health Organization (WHO) has recently approved a revision of the classification of new anti-TB drugs based on current evidence on each drug. In the previous WHO guidelines, the choice of drugs was based on efficacy and toxicity in a step-down manner, from group 1 first-line drugs and groups 2-5 second-line drugs, to group 5 drugs with potentially limited efficacy or limited clinical evidence. In the revised WHO classification, exclusively aimed at managing drug-resistant cases, medicines are again listed in hierarchical order from group A to group D. In parallel, a possible future classification is independently proposed. The aim of this viewpoint article is to describe the evolution in WHO TB classification (taking into account an independently proposed new classification) and recent changes in WHO guidance, while commenting on the differences between them. The latest evidence on the ex-group 5 drugs is also discussed

Statistical Laws Governing Fluctuations in Word Use from Word Birth to Word Death

We analyze the dynamic properties of 10^7 words recorded in English, Spanish and Hebrew over the period 1800--2008 in order to gain insight into the coevolution of language and culture. We report language independent patterns useful as benchmarks for theoretical models of language evolution. A significantly decreasing (increasing) trend in the birth (death) rate of words indicates a recent shift in the selection laws governing word use. For new words, we observe a peak in the growth-rate fluctuations around 40 years after introduction, consistent with the typical entry time into standard dictionaries and the human generational timescale. Pronounced changes in the dynamics of language during periods of war shows that word correlations, occurring across time and between words, are largely influenced by coevolutionary social, technological, and political factors. We quantify cultural memory by analyzing the long-term correlations in the use of individual words using detrended fluctuation analysis.Comment: Version 1: 31 pages, 17 figures, 3 tables. Version 2 is streamlined, eliminates substantial material and incorporates referee comments: 19 pages, 14 figures, 3 table

Random Matrix Theory and Chiral Symmetry in QCD

Random matrix theory is a powerful way to describe universal correlations of eigenvalues of complex systems. It also may serve as a schematic model for disorder in quantum systems. In this review, we discuss both types of applications of chiral random matrix theory to the QCD partition function. We show that constraints imposed by chiral symmetry and its spontaneous breaking determine the structure of low-energy effective partition functions for the Dirac spectrum. We thus derive exact results for the low-lying eigenvalues of the QCD Dirac operator. We argue that the statistical properties of these eigenvalues are universal and can be described by a random matrix theory with the global symmetries of the QCD partition function. The total number of such eigenvalues increases with the square root of the Euclidean four-volume. The spectral density for larger eigenvalues (but still well below a typical hadronic mass scale) also follows from the same low-energy effective partition function. The validity of the random matrix approach has been confirmed by many lattice QCD simulations in a wide parameter range. Stimulated by the success of the chiral random matrix theory in the description of universal properties of the Dirac eigenvalues, the random matrix model is extended to nonzero temperature and chemical potential. In this way we obtain qualitative results for the QCD phase diagram and the spectrum of the QCD Dirac operator. We discuss the nature of the quenched approximation and analyze quenched Dirac spectra at nonzero baryon density in terms of an effective partition function. Relations with other fields are also discussed.Comment: invited review article for Ann. Rev. Nucl. Part. Sci., 61 pages, 11 figures, uses ar.sty (included); references added and typos correcte

Languages cool as they expand: Allometric scaling and the decreasing need for new words

We analyze the occurrence frequencies of over 15 million words recorded in millions of books published during the past two centuries in seven different languages. For all languages and chronological subsets of the data we confirm that two scaling regimes characterize the word frequency distributions, with only the more common words obeying the classic Zipf law. Using corpora of unprecedented size, we test the allometric scaling relation between the corpus size and the vocabulary size of growing languages to demonstrate a decreasing marginal need for new words, a feature that is likely related to the underlying correlations between words. We calculate the annual growth fluctuations of word use which has a decreasing trend as the corpus size increases, indicating a slowdown in linguistic evolution following language expansion. This ‘‘cooling pattern’’ forms the basis of a third statistical regularity, which unlike the Zipf and the Heaps law, is dynamical in nature

Accountable to the community? Medieval officials in Castile: the perspective from below

The article discusses the role of the population in shifting the accountability of officials from the private to the public sphere in the late medieval period, when these procedures proliferated across Europe. It focuses on Castile in a European perspective as an example of two revealing developments: first, the role of urban representatives in legislation that ensured royal officials would account at the end of their term of office in the localities – despite the reticence of the Crown. Second, it points to flexibility in the use of this procedure, known as residencia and based on sindacato, employed at the discretion of communities and not exclusively at that of the elites. The article advocates reflection on the importance of the population at large generally in enforcing procedures that placed accountability in the hands of the public, and the adoption of a ‘bottom up’ approach to this topic