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THE PIONEERING CONTRIBUTIONS AND LEGACY OF WALDO H. ZAGWIJN (1928-2018)
Professor Dr. Waldo H. Zagwijn passed away on 26 June, 2018, in his ninetieth year. His thesis research (Zagwijn, 1960) stimulated palynological investigations into the Pliocene and early Quaternary, and caused a fundamental shift in our under-standing of the transition from the warm and relatively stable climate of the late Neogene to the extreme glacial-interglacial oscilla-tions of the early Quaternary. Distinct in several aspects from the usual methodologies of that time, Zagwijn’s approach can be summarized as:
focusing on establishing the botanical identification of pollen grains, following the guiding approach of his supervisor F. Flor-schütz, using botanical nomenclature to highlight these identifications and clarifying relationships between botany and the ear-lier artificial pollen nomenclature;
comprehensive and continuous attention to plant macroremains (fruits, seeds, etc.; Zagwijn, 1990) as a mean of integrating classical palaeobotany with modern palynology;
palaeoenvironmental interpretations informed by a deep understanding of modern plant ecology and associations;
leading investigations in the field, and paying special attention to stratigraphic correlations between (onshore and offshore) boreholes and exposed sections in quarries, using a range of available proxies including heavy mineral analysis.
Waldo H. Zagwijn was a visionary in realizing how modern palynology can be used for vegetational and climatic reconstructions in the Neogene, and indeed as far back as Paleogene times
Dynamical effects in the vibrationally resolved C 2s-1 photoionization cross section ratios of Methane
The vibrationally resolved C 2s photoionization cross-section of methane was investigated both theoretically and experimentally. When compared to that of C 1s photoionization, a rather different pattern has been observed, suggesting a strong interplay between the electron diffraction and interference effects
Trackways of the American Crocodile (Crocodylus acutus) in Northwestern Costa Rica: Implications for Crocodylian Ichnology
We documented trackways of free-living Crocodylus acutus on beaches at the mouths of Tamarindo and Ventanas estuaries, Costa Rica. Our crocodiles had estimated total lengths of 1–3 meters or more. Manus prints have five digits, with digits I–III bearing claw marks. Pes prints have four digits, with claw marks on digits I–III. The pes is plantigrade. Claws generally dig into the substrate. Apart from claw marks, digit I and the heel of the pes are usually the most deeply impressed parts of footprints. Trackways are wide-gauge. Pes prints are usually positioned just behind ipsilateral manus prints of the same set and may overlap them. Manus and pes prints angle slightly outward with respect to the crocodile’s direction of movement. Claw-bearing digits of both the manus and pes may create curved, concave-toward-the-midline drag marks as the autopodium is protracted. The tail mark varies in depth and clarity, and in shape from nearly linear to markedly sinuous. Sometimes the tail mark hugs the trackway midline, but sometimes it is closer to, or even cuts across, prints of one side. American crocodile footprints and trackways are similar to those observed in other extant crocodylian species, indicating substantial trackway conservatism across the grou
A Single-Arm, Proof-Of-Concept Trial of Lopimune (Lopinavir/Ritonavir) as a Treatment for HPV-Related Pre-Invasive Cervical Disease
BACKGROUND:
Cervical cancer is the most common female malignancy in the developing nations and the third most common cancer in women globally. An effective, inexpensive and self-applied topical treatment would be an ideal solution for treatment of screen-detected, pre-invasive cervical disease in low resource settings.
METHODS:
Between 01/03/2013 and 01/08/2013, women attending Kenyatta National Hospital's Family Planning and Gynaecology Outpatients clinics were tested for HIV, HPV (Cervista®) and liquid based cervical cytology (LBC -ThinPrep®). HIV negative women diagnosed as high-risk HPV positive with high grade squamous intraepithelial lesions (HSIL) were examined by colposcopy and given a 2 week course of 1 capsule of Lopimune (CIPLA) twice daily, to be self-applied as a vaginal pessary. Colposcopy, HPV testing and LBC were repeated at 4 and 12 weeks post-start of treatment with a final punch biopsy at 3 months for histology. Primary outcome measures were acceptability of treatment with efficacy as a secondary consideration.
RESULTS:
A total of 23 women with HSIL were treated with Lopimune during which time no adverse reactions were reported. A maximum concentration of 10 ng/ml of lopinavir was detected in patient plasma 1 week after starting treatment. HPV was no longer detected in 12/23 (52.2%, 95%CI: 30.6-73.2%). Post-treatment cytology at 12 weeks on women with HSIL, showed 14/22 (63.6%, 95%CI: 40.6-82.8%) had no dysplasia and 4/22 (18.2%, 95%CI: 9.9-65.1%) were now low grade demonstrating a combined positive response in 81.8% of women of which 77.8% was confirmed by histology. These data are supported by colposcopic images, which show regression of cervical lesions.
CONCLUSIONS:
These results demonstrate the potential of Lopimune as a self-applied therapy for HPV infection and related cervical lesions. Since there were no serious adverse events or detectable post-treatment morbidity, this study indicates that further trials are clearly justified to define optimal regimes and the overall benefit of this therapy.
TRIAL REGISTRATION:
ISRCTN Registry 48776874
Spin and Statistics and First Principles
It was shown in the early Seventies that, in Local Quantum Theory (that is
the most general formulation of Quantum Field Theory, if we leave out only the
unknown scenario of Quantum Gravity) the notion of Statistics can be grounded
solely on the local observable quantities (without assuming neither the
commutation relations nor even the existence of unobservable charged field
operators); one finds that only the well known (para)statistics of Bose/Fermi
type are allowed by the key principle of local commutativity of observables. In
this frame it was possible to formulate and prove the Spin and Statistics
Theorem purely on the basis of First Principles.
In a subsequent stage it has been possible to prove the existence of a
unique, canonical algebra of local field operators obeying ordinary Bose/Fermi
commutation relations at spacelike separations. In this general guise the Spin
- Statistics Theorem applies to Theories (on the four dimensional Minkowski
space) where only massive particles with finite mass degeneracy can occur. Here
we describe the underlying simple basic ideas, and briefly mention the
subsequent generalisations; eventually we comment on the possible validity of
the Spin - Statistics Theorem in presence of massless particles, or of
violations of locality as expected in Quantum Gravity.Comment: Survey based on a talk given at the Meeting on "Theoretical and
experimental aspects of the spin - statistics connection and related
symmetries", Trieste, Italy - October 21-25, 200
An overview of early investigational drugs for the treatment of human papilloma virus infection and associated dysplasia
Introduction: High-risk HPV (HR-HPV) related invasive cervical cancer (ICC) causes >270,000 deaths per annum world-wide with over 85% of these occurring in low-resource countries. Ablative and excisional treatment modalities are restricted for use with high-grade pre-cancerous cervical disease with HPV infection and low-grade dysplasia mostly managed by a watch-and-wait policy.Areas Covered: Various pharmacological approaches have been investigated as non-destructive alternatives for the treatment of HR-HPV infection and associated dysplasia. These are discussed dealing with efficacy, ease-of-use (physician or self-applied), systemic or locally applied, side-effects, cost and risks. The main focus is the perceived impact on current clinical practice of a self-applied, effective and safe pharmacological anti-HPV treatment.Expert opinion: Current prophylactic HPV vaccines are expensive, HPV type restricted and have little effect in already infected women. Therapeutic vaccines are under development but are also HPV type-restricted. At present, the developed nations use national cytology screening and surgical procedures to treat only women identified with HPV-related high-grade dysplastic disease. However, since HPV testing is rapidly replacing cytology as the test-of-choice, a suitable topically-applied and low-cost antiviral treatment could be an ideal solution for treatment of HPV infection per se with test-of-cure carried out by repeat HPV testing. Cytology would only then be necessary for women who remained HPV positive. Although of significant benefit in the developed countries, combining such a treatment with self-sampled HPV testing could revolutionise the management of this disease in the developing world which lack both the infrastructure and resources to establish national cytology screening programs
Using a theory of planned behaviour framework to explore hand hygiene beliefs at the '5 critical moments' among Australian hospital-based nurses 59
© 2015 White et al. Background: Improving hand hygiene among health care workers (HCWs) is the single most effective intervention to reduce health care associated infections in hospitals. Understanding the cognitive determinants of hand hygiene decisions for HCWs with the greatest patient contact (nurses) is essential to improve compliance. The aim of this study was to explore hospital-based nurses ' beliefs associated with performing hand hygiene guided by the World Health Organization's (WHO) 5 critical moments. Using the belief-base framework of the Theory of Planned Behaviour, we examined attitudinal, normative, and control beliefs underpinning nurses' decisions to perform hand hygiene according to the recently implemented national guidelines. Methods: Thematic content analysis of qualitative data from focus group discussions with hospital-based registered nurses from 5 wards across 3 hospitals in Queensland, Australia. Results: Important advantages (protection of patient and self), disadvantages (time, hand damage), referents (supportive: patients, colleagues; unsupportive: some doctors), barriers (being too busy, emergency situations), and facilitators (accessibility of sinks/products, training, reminders) were identified. There was some equivocation regarding the relative importance of hand washing following contact with patient surroundings. Conclusions: The belief base of the theory of planned behaviour provided a useful framework to explore systematically the underlying beliefs of nurses ' hand hygiene decisions according to the 5 critical moments, allowing comparisons with previous belief studies. A commitment to improve nurses' hand hygiene practice across the 5 moments should focus on individual strategies to combat distraction from other duties, peer-based initiatives to foster a sense of shared responsibility, and management-driven solutions to tackle staffing and resource issues. Hand hygiene following touching a patient's surroundings continues to be reported as the most neglected opportunity for compliance
Dual-gated bilayer graphene hot electron bolometer
Detection of infrared light is central to diverse applications in security,
medicine, astronomy, materials science, and biology. Often different materials
and detection mechanisms are employed to optimize performance in different
spectral ranges. Graphene is a unique material with strong, nearly
frequency-independent light-matter interaction from far infrared to
ultraviolet, with potential for broadband photonics applications. Moreover,
graphene's small electron-phonon coupling suggests that hot-electron effects
may be exploited at relatively high temperatures for fast and highly sensitive
detectors in which light energy heats only the small-specific-heat electronic
system. Here we demonstrate such a hot-electron bolometer using bilayer
graphene that is dual-gated to create a tunable bandgap and
electron-temperature-dependent conductivity. The measured large electron-phonon
heat resistance is in good agreement with theoretical estimates in magnitude
and temperature dependence, and enables our graphene bolometer operating at a
temperature of 5 K to have a low noise equivalent power (33 fW/Hz1/2). We
employ a pump-probe technique to directly measure the intrinsic speed of our
device, >1 GHz at 10 K.Comment: 5 figure
DINOSAUR FOOTPRINTS FROM THE GLEN ROSE FORMATION (PALUXY RIVER, DINOSAUR VALLEY STATE PARK, SOMERVELL COUNTY, TEXAS)
Dinosaur footprints are found in the Glen Rose Formation and other Lower Cretaceous stratigraphic units over much of central Texas (Pittman, 1989; Rogers, 2002; Farlow et al., 2006). Dinosaur tracks
were discovered in the rocky bed of the Paluxy River, near the town of Glen Rose, Texas, early in the 20th Century (Jasinski, 2008; Farlow et al., 2012b). Ellis W. Shuler of Southern Methodist University did pioneering studies on the dinosaur tracks (Shuler 1917, 1935, 1937), and Langston (1974) summarized much of the early literature.
What really put the dinosaur footprints of the Paluxy River on the map, though, were the herculean efforts that Roland T. Bird of the American Museum of Natural History made to secure trackway slabs for display at that institution and at the Texas Memorial Museum in Austin (Bird, 1985; Jasinski, 2008). In 1970 Dinosaur Valley State Park was created to protect the dinosaur footprints.
This guidebook briefly summarizes earlier work, and also serves as an interim report of research of our group still in progress, concerned with identifying the makers of the Paluxy River footprints, and determining what those animals were up to as they made their tracks. We will offer some comparisons of the dinosaur tracks of the Glen Rose Formation with those from other ichnofaunas around the world. The last quarter-century has seen an explosive increase in the technical literature dealing with dinosaur footprints, and we cannot possibly cite all of the relevant studies. For the sake of brevity we will emphasize publications from the present century, and summary papers and books, as much as possible. Even with this restriction, however, the literature is so vast that the literature-cited “tail” of this report starts to wag the “dog” of the text
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