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Smallpox, caused by the solely human pathogen Variola virus (VARV), was declared eradicated in 1980. While known VARV stocks are secure, smallpox remains a bioterrorist threat agent. Recent U.S. Food and Drug Administration approval of the first smallpox anti-viral (tecovirimat) therapeutic was a successful step forward in smallpox preparedness; however, orthopoxviruses can become resistant to treatment, suggesting a multi-therapeutic approach is necessary. Animal models are required for testing medical countermeasures (MCMs) and ideally MCMs are tested directly against the pathogen of interest. Since VARV only infects humans, a representative animal model for testing therapeutics directly against VARV remains a challenge. Here we show that three different humanized mice strains are highly susceptible to VARV infection, establishing the first small animal model using VARV. In comparison, the non-humanized, immunosuppressed background mouse was not susceptible to systemic VARV infection. Following an intranasal VARV challenge that mimics the natural route for human smallpox transmission, the virus spread systemically within the humanized mouse before mortality (~ 13 days post infection), similar to the time from exposure to symptom onset for ordinary human smallpox. Our identification of a permissive/representative VARV animal model can facilitate testing of MCMs in a manner consistent with their intended use., Author summary Preparedness activities against highly transmissible respiratory viruses with high mortality have been highlighted during the ongoing COVID-19 pandemic. Smallpox, caused by Variola virus (VARV) infection, is highly transmissible and estimated to have killed 300 million people in the 20th century alone with ~30% mortality. Through an intensive vaccination campaign smallpox was declared eradicated in 1980 and routine smallpox vaccination of individuals ceased. Today’s population has little/no immunity against VARV; if smallpox were to re-emerge the worldwide results would be devastating. Development of antiviral strategies is critical for outbreak response efforts and in order to truly gauge the potential effectiveness of a medical countermeasure (MCM), it must be tested directly against the pathogen. VARV is solely a human pathogen and infections of surrogate animal models have been largely unsuccessful. Here we use the humanized mouse to establish the first small animal model using VARV. We found that the virus spread systemically within humanized mice before mortality (~ 13 days post infection), similar to the time from exposure to symptom onset for ordinary human smallpox. These findings improve upon current MCM efficacy testing methods by providing a means to conduct in vivo evaluations of smallpox MCMs directly against VARV.

To accurately attribute sources and sinks of molecules like CO(2), remote sensing missions require line intensities (S) with relative uncertainties u(r) (S) < 0.1 %. However, discrepancies in S of ≈1 % are common when comparing different experiments, thus limiting their potential impact. Here we report a cavity ring-down spectroscopy multi-instrument comparison which revealed that the hardware used to digitize analog ring-down signals caused variability in spectral integrals which yield S. Our refined approach improved measurement accuracy twenty-five-fold, resulting in u(r)(S) = 0.06 %.

The potential influence of vasectomy being a risk factor for the development of prostate cancer is not a new concept, with more than 30 publications addressing the topic. Given the global frequency of vasectomy and the prevalence of prostate cancer, this subject justifiably deserves scrutiny. Several articles have claimed that vasectomy puts men at risk for future development of prostate cancer. We explore articles that have shown the contrary (no link), explore the studies' strengths and weaknesses, describe possible prostate cancer pathophysiologic mechanisms, and apply Bradford Hill criteria to help discern correlation with causation. The risk and interest of association of prostate cancer with vasectomy has waxed and waned over the last three decades. Based on our review, vasectomy remains a safe form of sterilization and does not increase prostate cancer risk.

In this article we describe a high-precision laboratory measurement targeting the R(6) manifold of the 2ν3 band of 12CH4. Accurate physical models of this absorption spectrum will be required by the Franco-German, Methane Remote Sensing LIDAR (MERLIN) space mission for retrievals of atmospheric methane. The analysis uses the Hartmann-Tran profile for modeling line shape and also includes line-mixing effects. To this end, six high-resolution and high signal-to-noise absorption spectra of air-broadened methane were recorded using a frequency-stabilized cavity ring-down spectroscopy apparatus. Sample conditions corresponded to room temperature and spanned total sample pressures of 40 hPa – 1013 hPa with methane molar fractions between 1 μmol mol−1 and 12 μmol mol−1. All spectroscopic model parameters were simultaneously adjusted in a multispectrum nonlinear least-squares fit to the six measured spectra. Comparison of the fitted model to the measured spectra reveals the ability to calculate the room-temperature, methane absorption coefficient to better than 0.1% at the on-line position of the MERLIN mission. This is the first time that such fidelity has been reached in modeling methane absorption in the investigated spectral region, fulfilling the accuracy requirements of the MERLIN mission. We also found excellent agreement when comparing the present results with measurements obtained over different pressure conditions and using other laboratory techniques. Finally, we also evaluated the impact of these new spectral parameters on atmospheric transmissions spectra calculations.

Accurate and spectroscopic measurements of molecular transition frequencies are increasingly being employed in a variety of rigorous tests of physics, including the validity of quantum electrodynamics, the proton–electron mass ratio, and the dipole moment of the electron. Near-infrared molecular transitions may also underpin secondary frequency standards for length metrology and provide convenient wavelength standards for telecommunication and spectroscopy. To report progress in this field, we describe measurements of near-infrared Doppler-broadened carbon dioxide line positions. Our experiment uses cavity ring-down spectroscopy in the linear domain and provides an accurate International System of Units (SI)-traceable frequency axis via active locking of the probe laser and ring-down cavity to a Cs-clock-referenced optical frequency comb. The approach has several key attributes: the ability to rapidly scan the probe laser while maintaining a phase lock to the optical frequency comb, continuously tunable spectrum frequency axes that are not limited by the cavity mode spacing, and high signal-to-noise-ratio spectra resulting in stationary statistics amenable to long-term averaging. This performance is achieved by phase locking a single-mode probe laser to the optical frequency comb, coherent electro-optical phase modulation for rapid cavity mode-to-mode shifting of the probe laser, and sub-kilohertz-level frequency stabilization of the ring-down cavity relative to the probe laser. We report vacuum transition frequencies of five transitions in the ( 30012 ) ← ( 00001 ) vibrational band of 12 C 16 O 2 near 1.57 µm and achieve combined standard uncertainties as low as 212 Hz, corresponding to a relative combined standard uncertainty near 10 − 12 .

Outbreaks can be prevented with strict biosecurity and microbiological monitoring., We investigated the extent of lymphocytic choriomeningitis virus (LCMV) infection in employees and rodents at 3 commercial breeding facilities. Of 97 employees tested, 31 (32%) had IgM and/or IgG to LCMV, and aseptic meningitis was diagnosed in 4 employees. Of 1,820 rodents tested in 1 facility, 382 (21%) mice (Mus musculus) had detectable IgG, and 13 (0.7%) were positive by reverse transcription PCR; LCMV was isolated from 8. Rats (Rattus norvegicus) were not found to be infected. S-segment RNA sequence was similar to strains previously isolated in North America. Contact by wild mice with colony mice was the likely source for LCMV, and shipments of infected mice among facilities spread the infection. The breeding colonies were depopulated to prevent further human infections. Future outbreaks can be prevented with monitoring and management, and employees should be made aware of LCMV risks and prevention.

Monkeypox (MPXV) and cowpox (CPXV) are emerging agents that cause severe human infections on an intermittent basis, and variola virus (VARV) has potential for use as an agent of bioterror. Vaccinia immune globulin (VIG) has been used therapeutically to treat severe orthopoxvirus infections but is in short supply. We generated a large panel of orthopoxvirus-specific human monoclonal antibodies (Abs) from immune subjects to investigate the molecular basis of broadly neutralizing antibody responses for diverse orthopoxviruses. Detailed analysis revealed the principal neutralizing antibody specificities that are cross-reactive for VACV, CPXV, MPXV, and VARV and that are determinants of protection in murine challenge models. Optimal protection following respiratory or systemic infection required a mixture of Abs that targeted several membrane proteins, including proteins on enveloped and mature virion forms of virus. This work reveals orthopoxvirus targets for human Abs that mediate cross-protective immunity and identifies new candidate Ab therapeutic mixtures to replace VIG.

Dual-comb spectroscopy allows for the rapid, multiplexed acquisition of high-resolution spectra without the need for moving parts or low-resolution dispersive optics. This method of broadband spectroscopy is most often accomplished via tight phase locking of two mode-locked lasers or via sophisticated signal processing algorithms, and therefore, long integration times of phase coherent signals are difficult to achieve. Here we demonstrate an alternative approach to dual-comb spectroscopy using two phase modulator combs originating from a single continuous-wave laser capable of > 2 hours of coherent real-time averaging. The dual combs were generated by driving the phase modulators with step-recovery diodes where each comb consisted of > 250 teeth with 203 MHz spacing and spanned > 50 GHz region in the near-infrared. The step-recovery diodes are passive devices that provide low-phase-noise harmonics for efficient coupling into an enhancement cavity at picowatt optical powers. With this approach, we demonstrate the sensitivity to simultaneously monitor ambient levels of CO2, CO, HDO, and H2O in a single spectral region at a maximum acquisition rate of 150 kHz. Robust, compact, low-cost and widely tunable dual-comb systems could enable a network of distributed multiplexed optical sensors., 11 pages, 4 figures

More than 26,000 cases of Ebola virus disease (EVD) have been reported in western Africa, with high mortality. Several patients have been medically evacuated to hospitals in the United States and Europe. Detailed clinical data are limited on the clinical course and management of patients with EVD outside western Africa.To describe the clinical characteristics and management of a cluster of patients with EVD, including the first cases of Ebola virus (EBOV) infection acquired in the United States.Retrospective clinical case series.Three U.S. hospitals in September and October 2014.First imported EVD case identified in the United States and 2 secondary EVD cases acquired in the United States in critical care nurses who cared for the index case patient.Clinical recovery, EBOV RNA level, resolution of Ebola viremia, survival with discharge from hospital, or death.The index patient had high EBOV RNA levels, developed respiratory and renal failure requiring critical care support, and died. Both patients with secondary EBOV infection had nonspecific signs and symptoms and developed moderate illness; EBOV RNA levels were moderate, and both patients recovered.Both surviving patients received uncontrolled treatment with multiple investigational agents, including convalescent plasma, which limits generalizability of the results.Early diagnosis, prompt initiation of supportive medical care, and moderate clinical illness likely contributed to successful outcomes in both survivors. The inability to determine the potential benefit of investigational therapies and the effect of patient-specific factors that may have contributed to less severe illness highlight the need for controlled clinical studies of these interventions, especially in the setting of a high level of supportive medical care.None.

Understanding of today's climate and predictions of future climate require accurate input data to model the energy balance between the sun's irradiance and Earth’s atmosphere, oceans, land, and surface ice. An important driver of climate change is the absorption and scattering of sunlight by carbon-based aerosols (soot, smoke, etc) that have widely-varying, source-dependent, and history-dependent optical properties. We use a resonant photoacoustic spectrometer (PAS) to measure the optical absorption cross-section of various carbonaceous aerosols that we generate and characterize in situ. The photoacoustic signal is directly proportional to the energy absorbed by the particles. When combined with simultaneous measurements of the total extinction using cavity ring-down spectroscopy, we obtain the particles’ wavelength-dependent albedo (fraction of incident light scattered). Another important driver of climate change is atmospheric carbon dioxide, a greenhouse gas. With the remarkable linearity, sensitivity,...

The first known Ebola hemorrhagic fever (EHF) outbreak caused by Bundibugyo Ebola virus occurred in Bundibugyo District, Uganda, in 2007. Fifty-six cases of EHF were laboratory confirmed. Although signs and symptoms were largely nonspecific and similar to those of EHF outbreaks caused by Zaire and Sudan Ebola viruses, proportion of deaths among those infected was lower (≈40%). publishedVersion

In July and September 2007, miners working in Kitaka Cave, Uganda, were diagnosed with Marburg hemorrhagic fever. The likely source of infection in the cave was Egyptian fruit bats (Rousettus aegyptiacus) based on detection of Marburg virus RNA in 31/611 (5.1%) bats, virus-specific antibody in bat sera, and isolation of genetically diverse virus from bat tissues. The virus isolates were collected nine months apart, demonstrating long-term virus circulation. The bat colony was estimated to be over 100,000 animals using mark and re-capture methods, predicting the presence of over 5,000 virus-infected bats. The genetically diverse virus genome sequences from bats and miners closely matched. These data indicate common Egyptian fruit bats can represent a major natural reservoir and source of Marburg virus with potential for spillover into humans., Author Summary Marburg virus, similar to its close cousin Ebola virus, can cause large outbreaks of hemorrhagic fever (HF) in rural Africa with case fatalities approaching 90%. For decades, a long-standing enigma has been the identity of the natural reservoir of this deadly virus. In this report, we identify the cave-dwelling Egyptian fruit bat (Rousettus aegyptiacus) as a natural host of Marburg virus based on multiple lines of evidence which include, for the first time ever, the isolation of virus directly from wild-caught and apparently healthy bats. The species R. aegyptiacus is common throughout Africa with distribution into the eastern Mediterranean and Middle East. Our finding of active virus infection in approximately 5% of R. aegyptiacus bats and their population exceeding 100,000 in Kitaka cave in Uganda suggests there are likely over 5,000 Marburg virus–infected bats in this cave, which is only one of many such cave populations throughout Africa. Clearly, these bats could serve as a major source of virus with potential to initiate human epidemics, and the implications for public health are striking. Additionally, we found highly divergent (21%) genome sequences among viruses circulating in these bat populations, a level of diversity that would result from a long-term association with a suitable reservoir host of large population size.

Marburg virus (family Filoviridae) causes sporadic outbreaks of severe hemorrhagic disease in sub-Saharan Africa. Bats have been implicated as likely natural reservoir hosts based most recently on an investigation of cases among miners infected in 2007 at the Kitaka mine, Uganda, which contained a large population of Marburg virus-infected Rousettus aegyptiacus fruit bats. Described here is an ecologic investigation of Python Cave, Uganda, where an American and a Dutch tourist acquired Marburg virus infection in December 2007 and July 2008. More than 40,000 R. aegyptiacus were found in the cave and were the sole bat species present. Between August 2008 and November 2009, 1,622 bats were captured and tested for Marburg virus. Q-RT-PCR analysis of bat liver/spleen tissues indicated ∼2.5% of the bats were actively infected, seven of which yielded Marburg virus isolates. Moreover, Q-RT-PCR-positive lung, kidney, colon and reproductive tissues were found, consistent with potential for oral, urine, fecal or sexual transmission. The combined data for R. aegyptiacus tested from Python Cave and Kitaka mine indicate low level horizontal transmission throughout the year. However, Q-RT-PCR data show distinct pulses of virus infection in older juvenile bats (∼six months of age) that temporarily coincide with the peak twice-yearly birthing seasons. Retrospective analysis of historical human infections suspected to have been the result of discrete spillover events directly from nature found 83% (54/65) events occurred during these seasonal pulses in virus circulation, perhaps demonstrating periods of increased risk of human infection. The discovery of two tags at Python Cave from bats marked at Kitaka mine, together with the close genetic linkages evident between viruses detected in geographically distant locations, are consistent with R. aegyptiacus bats existing as a large meta-population with associated virus circulation over broad geographic ranges. These findings provide a basis for developing Marburg hemorrhagic fever risk reduction strategies., Author Summary Marburg virus, like its close relative Ebola virus, can cause large outbreaks of hemorrhagic fever with case fatalities nearing 90%. For decades the identity of the natural reservoir was unknown. However, in 2007 Marburg viruses were isolated directly from Egyptian fruit bats (Rousettus aegyptiacus) that inhabited a Ugandan gold mine where miners were previously infected. Soon after, two tourists became infected with Marburg virus after visiting nearby Python Cave, a popular attraction in Queen Elizabeth National Park, Uganda. This cave also contained R. aegyptiacus bats (∼40,000 animals). These events prompted a long-term investigation of Python Cave to determine if, 1) R. aegyptiacus in the cave carried infectious Marburg virus genetically similar to that found in the tourists, and 2) what ecological factors might influence virus spillover to humans. In the study, we found that, 1) approximately 2.5% of the bat colony is actively infected at any one time and that virus isolates from bats are genetically similar to those from infected tourists, and 2) specific age groups of bats (juveniles∼six months of age) are particularly likely to be infected at specific times of the year that roughly coincide with historical dates of Marburg virus spillover into humans.

The resonance elastic light scattering (RELS) spectroscopy has been applied to study the interactions of glutathione (GSH) with citrate-capped gold nanoparticles (AuNP). A strong dependence of GSH-induced gold nanoparticle assembly on nanoparticle size has been found. The RELS intensity measurements were carried out in a short reaction time (τ = 60 s) after injection of GSH. The strong interparticle interactions between AuNP are due to zwitterionic forces and intermolecular hydrogen bonding. The AuNP assembly has been confirmed using the surface plasmon UV-Vis spectroscopy. A fast initial adsorption rate of GSH on a clean Au surface, v = 2.4 ng cm-2 s-1, has been measured using a nanogravimetric flow-cell with piezoelectric QC/Au resonator. The adsorption/desorption processes have been evaluated. The RELS spectroscopy has been found as a very sensitive tool for studying interparticle interactions and its applications can be extended to monitor reactivities and assembly of other monolayer-protected metal clusters.

Homocysteine is a biomarker of oxidative stress and a risk factor for many disorders, including cardiovascular and Alzheimer's disease. We have investigated new methods for the development of homocysteine assays based on gold nanoparticles (AuNP) in solutions and modified solid gold piezoelectrodes. In this work, we have applied sensitive resonance elastic light scattering (RELS) and plasmonic UV-Vis spectroscopy to monitor homocysteine-induced AuNP assembly. The assembly of AuNP frameworks by covalent binding of interparticle glutaraldehyde nanobridges has been utilized for sensitive homocysteine determination. The selectivity of a glutaraldehyde crosslinking reactions toward homocysteine has been exploited to discriminate against other aminoacids. The measurements of a homocysteine adsorption on a solid Au electrode, carried out using the electrochemical quartz crystal nanogravimetry (EQCN), have shown that a multilayer film, with thickness of up to 3 equivalent monolayers, is formed in the zwitterionic pH range of homocysteine.

A new species of Ebolavirus, Bundibugyo ebolavirus, was discovered in an outbreak in western Uganda in November 2007. To study the correlation between fatal infection and immune response in Bundibugyo ebolavirus infection, viral antigen, antibodies, and 17 soluble factors important for innate immunity were examined in 44 patient samples. Using Luminex assays, we found that fatal infection was associated with high levels of viral antigen, low levels of pro-inflammatory cytokines, such as IL-1α, IL-1β, IL-6, TNF-α, and high levels of immunosuppressor cytokines like IL-10. Also, acute infected patients died in spite of generating high levels of antibodies against the virus. Thus, our results imply that disease severity in these patients is not due to the multi-organ failure and septic shock caused by a flood of inflammatory cytokines, as seen in infections with other Ebolavirus species.