464 research outputs found
Theresienstadt: A Geographical Picture of Transports, Demography, and Communicable Disease in a Jewish Camp-Ghetto, 1941ā45
The Nazi ghetto system was one of the principal vehicles for the persecution of Jewish and other peoples in German-occupied Europe in World War II. Transport and confinement ā twin pillars of the ghetto system ā were intrinsically geographical matters that operated on scales from the international to the local and which shaped the demographic and epidemiological character of ghettos across Eastern Europe. This article uses geographical techniques of map-based visualisation and spatial analysis to portray the demographic and epidemic history of the Nazi āmodelā camp-ghetto at Theresienstadt (TerezĆn) in the former German Protectorate of Bohemia and Moravia, 1941ā45. Our study reconstructs the space-time pattern and demographic structure of transports of Jewish prisoners to the ghetto and their association with substantial outbreaks of communicable diseases in the ghetto. The study highlights the importance of a geographical approach to an understanding of the demographic and public health impacts of both the Holocaust and other genocidal events
Prospects for the measurement of the electron electric dipole moment using YbF
We discuss an experiment underway at Imperial College London to measure the
permanent electric dipole moment (EDM) of the electron using a molecular beam
of YbF. We describe the measurement method, which uses a combination of laser
and radiofrequency resonance techniques to detect the spin precession of the
YbF molecule in a strong electric field. We pay particular attention to the
analysis scheme and explore some of the possible systematic effects which might
mimic the EDM signal. Finally, we describe technical improvements which should
increase the sensitivity by more than an order of magnitude over the current
experimental limit.Comment: 6 pages, 2 figure
Suzbijanje geografskog Ŕirenja zaraze: kuga u Italiji od 1347.-1851.
After the establishment of the first quarantine station in the Republic of Ragusa (modern-day Dubrovnik) in 1377, the states and principalities of Italy developed a sophisticated system of defensive quarantine in an attempt to protect themselves from the ravages of plague. Using largely unknown and unseen historical maps, this paper reconstructs the extent and operation of the system used. It is shown that a cordon sanitaire existed around the coast of Italy for several centuries, consisting of three elements: (i) an outer defensive ring of armed sailing boats in the Mediterranean and the Adriatic, (ii) a middle coastal ring of forts and observation towers, and (iii) an inner defensive ring of land-based cavalry. The principles established, although not especially successful at the time against a disease of (then) unknown aetiology, are still used today in attempts to control the spread of infections of animal and human populations.Nakon uspostave prvoga lazareta u DubrovaÄkoj Republici 1377., talijanske državice i kneževine razradile su sustav karantena kako bi se zaÅ”titile od razarajuÄega djelovanja kuge. OslanjajuÄi se mahom na dosad nepoznate povijesne karte, u ovome se Älanku rekonstruira kako je i u kojem razmjeru djelovao sustav zaÅ”tite. Duž talijanske obale stoljeÄima je postojao sanitarni kordon, a sastojao se od tri dijela: (i) vanjski pojas sastavljen od naoružanih jedrenjaka na Sredozemnom i Jadranskome moru, (ii) srednji obrambeni pojas sastavljen od utvrda i promatraÄnica te (iii) unutarnji obrambeni pojas na kopnu sastavljen od konjice. Premda ovaj sustav svojevremeno i nije bio pretjerano uspjeÅ”an u zaÅ”titi od bolesti (tada) nepoznate etiologije, njegova se naÄela joÅ” uvijek rabe za sprjeÄavanje Å”irenja bolesti meÄu ljudima i životinjama
Continuous Flow Generation of Acylketene Intermediates via Nitrogen Extrusion
A flow chemistry process for the generation and use of acylketene precursors through extrusion of nitrogen gas is reported. Key to the development of a suitable continuous protocol is the balance of reaction concentration against pressure in the flow reactor. The resulting process enables access to intercepted acylketene scaffolds using volatile amine nucleophiles and has been demonstrated on the gram scale. Thermal gravimetric analysis was used to guide the temperature set point of the reactor coils for a variety of acyl ketene precursors. The simultaneous generation and reaction of two reactive intermediates (both derived from nitrogen extrusion) is demonstrated
Abrupt transition to heightened poliomyelitis epidemicity in England and Wales, 1947ā1957, associated with a pronounced increase in the geographical rate of disease propagation
The abrupt transition to heightened poliomyelitis epidemicity in England and Wales, 1947ā1957, was associated with a profound change in the spatial dynamics of the disease. Drawing on the complete record of poliomyelitis notifications in England and Wales, we use a robust method of spatial epidemiological analysis (swash-backwash model) to evaluate the geographical rate of disease propagation in successive poliomyelitis seasons, 1940ā1964. Comparisons with earlier and later time periods show that the period of heightened poliomyelitis epidemicity corresponded with a sudden and pronounced increase in the spatial rate of disease propagation. This change was observed for both urban and rural areas and points to an abrupt enhancement in the propensity for the geographical spread of polioviruses. Competing theories of the epidemic emergence of poliomyelitis in England and Wales should be assessed in the light of this evidence
Spatial Growth Rate of Emerging SARS-CoV-2 Lineages in England, September 2020-December 2021
This paper uses a robust method of spatial epidemiological analysis to assess the spatial growth rate of multiple lineages of SARS-CoV-2 in the local authority areas of England, September 2020-December 2021. Using the genomic surveillance records of the COVID-19 Genomics UK (COG-UK) Consortium, the analysis identifies a substantial (7.6-fold) difference in the average rate of spatial growth of 37 sample lineages, from the slowest (Delta AY.4.3) to the fastest (Omicron BA.1). Spatial growth of the Omicron (B.1.1.529 and BA) variant was found to be 2.81 Ć faster than the Delta (B.1.617.2 and AY) variant and 3.76Ć faster than the Alpha (B.1.1.7 and Q) variant. In addition to AY.4.2 (a designated variant under investigation, VUI-21OCT-01), three Delta sublineages (AY.43, AY.98 and AY.120) were found to display a statistically faster rate of spatial growth than the parent lineage and would seem to merit further investigation. We suggest that the monitoring of spatial growth rates is a potentially valuable adjunct to outbreak response procedures for emerging SARS-CoV-2 variants in a defined population
Deep coal mining and meningococcal meningitis in England and Wales, 1931ā38: ecological study, with implications for deep shaft mining activities worldwide
The hypothesized role of deep coal mining in the development of community-based outbreaks of meningococcal meningitis has gone largely unexplored. Taking the coalfields of Britain as a historical testbed, techniques of linear and binomial logistic regression were used to assess the association between meningococcal meningitis rates and male occupation rates for coal mining in England and Wales during the national epidemic of 1931ā32 and in its aftermath. Adjusting for the epidemiological effects of age, residential density, recent changes in the number of families, housing stock and low social class, the analysis yielded evidence of a significant and positive association between coal mining occupation rates and notified levels of meningitis activity in the epidemic period. Communities in areas of the world that currently maintain substantial deep coal extraction industries may be at increased risk for the epidemic transmission of meningococcal meningitis
Alternate trait-based leaf respiration schemes evaluated at ecosystem-scale through carbon optimization modeling and canopy property data
Leaf maintenance respiration (Rleaf,m) is a major but poorly understood component of the terrestrial carbon cycle (C). Earth systems models (ESMs) use simple subāmodels relating Rleaf,m to leaf traits, applied at canopy scale. Rleaf,m models vary depending on which leaf N traits they incorporate (e.g., mass or area based) and the form of relationship (linear or nonlinear). To simulate vegetation responses to global change, some ESMs include ecological optimization to identify canopy structures that maximize net C accumulation. However, the implications for optimization of using alternate leafāscale empirical Rleaf,m models are undetermined. Here we combine alternate wellāknown empirical models of Rleaf,m with a process model of canopy photosynthesis. We quantify how net canopy exports of C vary with leaf area index (LAI) and total canopy N (TCN). Using data from tropical and arctic canopies, we show that estimates of canopy Rleaf,m vary widely among the three models. Using an optimization framework, we show that the LAI and TCN values maximizing C export depends strongly on the Rleaf,m model used. No single model could match observed arctic and tropical LAIāTCN patterns with predictions of optimal LAIāTCN. We recommend caution in using leafāscale empirical models for components of ESMs at canopyāscale. Rleaf,m models may produce reasonable results for a specified LAI, but, due to their varied representations of Rleaf,mfoliar N sensitivity, are associated with different and potentially unrealistic optimization dynamics at canopy scale. We recommend ESMs to be evaluated using response surfaces of canopy C export in LAIāTCN space to understand and mitigate these risks
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