Establishing an SEIR-based framework for local modelling of COVID-19 infections, hospitalisations and deaths

Without timely assessments of the number of COVID-19 cases requiring hospitalisation, healthcare providers will struggle to ensure an appropriate number of beds are made available. Too few could cause excess deaths while too many could result in additional waits for elective treatment. As well as supporting capacity considerations, reliably projecting future "waves" is important to inform the nature, timing and magnitude of any localised restrictions to reduce transmission. In making the case for locally owned and locally configurable models, this paper details the approach taken by one major healthcare system in founding a multi-disciplinary "Scenario Review Working Group", comprising commissioners, public health officials and academic epidemiologists. The role of this group, which met weekly during the pandemic, was to define and maintain an evolving library of plausible scenarios to underpin projections obtained through an SEIR-based compartmental model. Outputs have informed decision-making at the system's major incident Bronze, Silver and Gold Commands. This paper presents illustrated examples of use and offers practical considerations for other healthcare systems that may benefit from such a framework.

Modelling the effect of first-wave COVID-19 on mental health services

During the first wave of the COVID-19 pandemic it emerged that the nature and magnitude of demand for mental health services was changing. Considerable increases were expected to follow initial lulls as treatment was sought for new and existing conditions following relaxation of 'lockdown' measures. For this to be managed by the various services that constitute a mental health system, it would be necessary to complement such projections with assessments of capacity, in order to understand the propagation of demand and the value of any consequent mitigations. This paper provides an account of exploratory modelling undertaken within a major UK healthcare system during the first wave of the pandemic, when actionable insights were in short supply and decisions were made under much uncertainty. In understanding the impact on post-lockdown operational performance, the objective was to evaluate the efficacy of two considered interventions against a baseline 'do nothing' scenario. In doing so, a versatile and purpose-built discrete time simulation model was developed, calibrated and used by a multi-disciplinary project working group. The solution, representing a multi-node, multi-server queueing network with reneging, is implemented in open-source software and is freely and publicly available.

A dose and time response Markov model for the in-host dynamics of infection with intracellular bacteria following inhalation: with application to Francisella tularensis

In a novel approach, the standard birth–death process is extended to incorporate a fundamental mechanism undergone by intracellular bacteria, phagocytosis. The model accounts for stochastic interaction between bacteria and cells of the immune system and heterogeneity in susceptibility to infection of individual hosts within a population. Model output is the dose–response relation and the dose-dependent distribution of time until response, where response is the onset of symptoms. The model is thereafter parametrized with respect to the highly virulent Schu S4 strain of Francisella tularensis, in the first such study to consider a biologically plausible mathematical model for early human infection with this bacterium. Results indicate a median infectious dose of about 23 organisms, which is higher than previously thought, and an average incubation period of between 3 and 7 days depending on dose. The distribution of incubation periods is right-skewed up to about 100 organisms and symmetric for larger doses. Moreover, there are some interesting parallels to the hypotheses of some of the classical dose–response models, such as independent action (single-hit model) and individual effective dose (probit model). The findings of this study support experimental evidence and postulations from other investigations that response is, in fact, influenced by both in-host and between-host variability.

Mitochondrial DNA divergence in the critically imperilled pygmy madtom, Noturus stanauli (Siluriformes: Ictaluridae)

The mitochondrial cytochrome b gene was sequenced for six individuals of the pygmy madtom, Noturus stanauli, a globally imperilled catfish, from both known localities in Tennessee (U.S.A.) separated by over 1055 river km. Phylogenetic and population genetic analyses revealed little divergence between these populations for this locus.

Tularemia in a mule deer

A case of tularemia was confirmed in a 51-year-old man who acquired the disease from a mule deer, Odocoileus hemionus. Francisella tularensis was isolated from bone marrow of the deer carcass.

Effects of aggregation and sample size on composite faecal egg counts in sheep

Composite faecal egg counts (FEC) are increasingly used to support strategic anthelmintic treatment decisions in grazing livestock. However, their accuracy as estimators of group mean FEC is affected by the number of individual samples included, how thoroughly they are mixed, and the underlying degree of parasite aggregation between individual hosts. This paper uses a Negative Binomial model for parasite aggregation, and a Poisson model for egg distribution within faecal suspensions, in order to optimise composite FEC protocol for commercial sheep flocks. Our results suggest that faecal egg density in a well-mixed composite sample from 10 sheep (3g of faeces from each), estimated by examination of four independently filled McMaster chambers, is likely to provide an adequate estimate of group mean FEC in the majority of situations. However, extra care is needed in groups of sheep for which high levels of FEC aggregation might be expected. The implications of statistical error in FEC estimates depend on how they are used. The simulation-based approach presented here is a powerful tool for investigating the risks of error in FEC-driven treatment decisions in different situations, as well as for the statistical analysis of parasitological data in general.

Infant crying and adults' anticipated caregiving responses: acoustic and contextual influences

These studies assessed adults' latencies to signal that they would respond to infant crying as functions of (1) the degree of infant distress they perceived in the cry, and (2) contextual information relevant to caregiving. In the first study (N = 34), listeners waited longer to respond to cries that they had earlier rated as sounding less distressed than when they heard cries of higher distress. Further, those who had been told that the infant needed sleep waited longer to respond than those without this information. This effect of context information, however, was limited to the latencies; in another study (N = 50), listeners' ratings of distress were not affected. Several acoustic features of the cries correlated with distress ratings and with latencies to signal a caregiving response. Taken together, the results suggest that adults' responses to crying are influenced both by acoustic gradations in the cry itself and by the caregiving context. Ratings of degree of distress manifest in the cry, in other words, may be highly predictive of caregiving behavior but not wholly so. Finally, although certain acoustic variations related to greater perceived distress and speed of response, differences were apparent between infants in the magnitude of these variations. The implication that the general process of cry perception may be calibrated, or fine tuned, to the range of acoustic variation provided by individual infants is discussed.

Antimurine immunoglobulin antibody responses after the administration of murine monoclonal antibodies to rats are altered by small bowel allograft rejection

BACKGROUND

This study monitored the induction of antimurine immunoglobulin antibody responses after the administration of anti-CD4 (OX38) and anti-LFA-1 (WT.1) monoclonal antibodies to DA rats.

METHODS

Monoclonal antibody was administered i.v. on 3 consecutive days to untransplanted DA rats, and DA recipients of PVG small bowel allografts. Control animals received no monoclonal antibody. Antimurine immunoglobulin antibody levels in serum samples were determined by enzyme immunoassay.

RESULTS

No antimurine immunoglobulin antibody was detected in untransplanted animals receiving OX38 alone. Reactivity was apparent in WT.1-treated animals, but this response was totally abrogated by the co-administration of OX38. A combination of OX38 and WT.1 had no effect on allograft recipient survival and antimurine immunoglobulin antibody responses were detected in all allograft recipients, irrespective of the treatment regimen.

CONCLUSIONS

Although OX38 inhibited the antibody response both to itself and to WT.1 in untransplanted animals, the immune reaction induced by small bowel allograft rejection overcame this inhibitory capacity.

Bond valence sums in coordination chemistry. Calculation of the oxidation state of chromium in complexes containing only Cr-O bonds and a redetermination of the crystal structure of potassium tetra(peroxo)chromate(V)

A simple method for calculating the oxidation state of Cr in complexes containing only Cr-O bonds is presented. A total of 242 CrOn fragments with n = 3-6 were retrieved from the Cambridge Structural Database (CSD) and, together with the data for K3CrO8, were analyzed using the bond valence sum method. New R0 values for Cr(II) of 1.739(21) A, Cr(III) of 1.708(7) A, Cr(V) of 1.762(14) A, and Cr(VI) of 1.793(7) A were derived. An average R0 value of 1.724 A for Cr-O reproduces the oxidation state of 96 of the 110 Cr(II), Cr(III), and Cr(IV) CrOn complexes (n = 3-6) and that of K3CrO8 within 0.30 valence units. The crystal structure of K3CrO8 was redetermined at 173 K to provide accurate data for a Cr complex with both high oxidation state and coordination number. Potassium tetraperoxochromate(V), K3CrO8, is tetragonal, Space group I42m, a = b = 6.6940(3) A, c = 7.7536(5) A, Z = 2. The difficulties with fitting the observed valence for Cr(V) and Cr(VI) complexes with coordination numbers 4 and 5 are discussed. The use of bond valence sums in gaining chemical insight into Cr complexes with noninnocent ligands and in establishing oxidation states in Cr clusters is presented. An analysis of the Cr-O bond distances used in the calculations shows a large range of values that can be understood in terms of the bond valence sum calculation.

Psychological assessment, treatment, and outcome with sex offenders

The frequency and impact of sexual offenses have led to the recent enactment of sexual "predator" laws. Such laws are intended to reduce sexual violence through treatment and involuntary confinement. Sixty years ago, similar laws identifying "sexual psychopaths" were enacted and, in many states, eventually repealed for multiple reasons; among those reasons was an inability to demonstrate that treatment had any significant impact on recidivism. That inability forced us to reexamine, among other issues, the population(s) which undergo treatment, the outcomes that are used to measure treatment effectiveness, and the processes that constitute treatment itself. Those issues are considered in this paper through a review of treatment programs based on psychodynamic, behavioral, and cognitive-behavioral theories. Although the evidence is sparse, it is fair to conclude that the latter have been found to be effective. We call for dynamic measures, effective treatments, and the resources necessary for both developments.

Pelosi-type vs. traditional cesarean delivery. A prospective comparison

OBJECTIVE

To determine the effect of a simplified method of cesarean delivery on postoperative febrile morbidity, operative time, blood loss, total cost and length of hospital stay at Yale New Haven Hospital.

STUDY DESIGN

From March 22, 1997, until September 26, 1997, 304 consecutive primary low transverse cesarean deliveries were evaluated at Yale New Haven Hospital. The patient age, duration of ruptured membranes, use of prophylactic antibiotics, operative times, blood loss, major complications, analgesic use, diet advancement, length of hospital stay and total cost of hospitalization were recorded for 275 eligible cases.

RESULTS

The Pelosi technique was employed in 101 cases, while 174 were performed with Yale's traditional methods. Both groups were comparable regarding demographic characteristics. Two women in the Pelosi group (1.98%) developed postoperative fevers as compared with 17 (9.77%) in the traditional group (relative risk, 4.93; confidence interval, 1.16, 20.91; P = .05). The mean operating time was 27 minutes in the Pelosi group versus 45 minutes in the traditional group (P = .01). The mean costs were $7,623.55 in the experimental group versus $8,613.28 in the controls (P = .001). No significant differences were seen between the use of prophylactic antibiotics, duration of membrane rupture, analgesic use or hospital stay between the two groups. No serious maternal or fetal outcomes occurred in either group.

CONCLUSION

Pelosi-type cesarean delivery resulted in significantly decreased operative time, blood loss and overall cost and improved patient outcome over traditional cesarean section.

Treatment of endometriosis involving a self-help group positively affects patients' perception of care

Chronic endometriosis is notoriously difficult to treat and many women become frustrated with their care. We established an Endometriosis Clinic as a co-operative venture between a group of gynecologists and a self-help group, the Endometriosis Association of Victoria. The aim of this study was to examine the clinical characteristics of women attending the clinic and to determine patient satisfaction with the clinic. The study involved a review of patient histories and a postal satisfaction questionnaire. Three hundred and fourteen women attended the clinic during its first year of operation. Seventy per cent had had a diagnosis of endometriosis made elsewhere and attended the clinic for a second opinion or for more information. Eighty-six per cent presented with symptoms suggestive of endometriosis, 8% presented with infertility and 6% complained of both symptoms and infertility. When patients were asked to score the overall service provided by the clinic on a scale of 1 to 10, scores ranged from 4 to 10 with a mean of 8.7. Ninety-seven per cent of women felt that the consultation with a counselor from the Endometriosis Association was a major source of satisfaction. We have documented a significant demand for and high patient satisfaction with the concept of integrating a patient self-help group in the standard model of health care for endometriosis.

Yeast glycolytic mRNAs are differentially regulated

The regulation of glycolytic genes in response to carbon source in the yeast Saccharomyces cerevisiae has been studied. When the relative levels of each glycolytic mRNA were compared during exponential growth on glucose or lactate, the various glycolytic mRNAs were found to be induced to differing extents by glucose. No significant differences in the stabilities of the PFK2, PGK1, PYK1, or PDC1 mRNAs during growth on glucose or lactate were observed. PYK::lacZ and PGK::lacZ fusions were integrated independently into the yeast genome at the ura3 locus. The manner in which these fusions were differentially regulated in response to carbon source was similar to that of their respective wild-type loci. Therefore, the regulation of glycolytic mRNA levels is mediated at the transcriptional level. When the mRNAs are ordered with respect to the glycolytic pathway, two peaks of maximal induction are observed at phosphofructokinase and pyruvate kinase. These enzymes (i) catalyze the two essentially irreversible steps on the pathway, (ii) are the two glycolytic enzymes that are circumvented during gluconeogenesis and hence are specific to glycolysis, and (iii) are encoded by mRNAs that we have shown previously to be coregulated at the translational level in S. cerevisiae (P. A. Moore, A. J. Bettany, and A. J. P. Brown, NATO ASI Ser. Ser. H Cell Biol. 49:421-432, 1990). This differential regulation of glycolytic mRNA levels might therefore have a significant influence upon glycolytic flux in S. cerevisiae.

Growth patterns in pediatric bone marrow transplant patients

There is little known about the long-term effects of the bone marrow transplantation process on the growth of pediatric patients. The purpose of this descriptive study was to examine one of the possible long-term effects of bone marrow transplantation: the effect of the bone marrow transplantation process on the growth curves of pediatric patients. A chart audit was completed on the medical records of 60 bone marrow transplant patients who were between the ages of 5 months to 13.9 years at the time of the transplant. Results indicated that approximately half of the subjects maintained their height percentiles, and a little less than half maintained their weight percentiles after the transplant. Results of this study suggest that further nursing research on the growth of pediatric bone marrow transplant patients is needed, and growth (height and weight) should be part of nursing nutritional assessment of pediatric bone marrow transplant patients.

Nutrition and the head and neck cancer patient

Patients with head and neck cancer have a unique nutritional problem that can affect their response to treatment. To properly manage these patients the oral and maxillofacial surgeon must be able to accurately assess their nutritional status and implement the proper metabolic treatment. This article reviews the benefits of nutritional support, the methods of patient assessment and nutritional repletion, and the advantages and disadvantages of the various alimentation modalities. Also, an analysis of the relationship of nutritional status and the surgical course of the head and neck cancer patient at our institution is presented.

Depression, somatization and steroid use in chronic obstructive pulmonary disease

Steroid therapy has become part of the adjunctive treatment for COPD patients in some settings. Emotional changes have been reported in some patients while on these medications, but whether these changes are associated with the pathophysiological state or a side effect of the medication is not known. In this study self-reports of depression and somatic complaints were compared between two groups of COPD patients, 20 not receiving steroids and 20 receiving steroids. Both groups demonstrated comparable levels of disease and somatic complaints. Mean FEV1 value for those not receiving steroids was 34% of predicted while the mean for those receiving steroids was 30% of predicted. Depression was found to be significantly higher (t = 11.21, df = 38, p less than 0.01) in the group receiving steroids when compared to those not receiving steroids using a Student's t test. The higher degree of depression among steroid treated COPD patients has implications for clinical practice. The emotional status of this group of patients needs to be monitored and interventions initiated when necessary.

The scandinavian earthquakes of 22 december 1759 and 31 august 1819

The two largest known pre-1850 Scandinavian earthquakes are the 22 December 1759 Kattegat event (located at 57.7°N-11.1°E) and the 31 August 1819 Nordland event (located at 66.4°N-14.4°E), the latter being the largest north European near-shore earthquake of the past few centuries. The 22 December 1759 event caused minor damage to buildings (MMIVII) on either side of the Kattegat in Northern Jutland and in the Swedish province ofBohuslän, and was felt up to 600 km away. The 31 August 1819 earthquake caused widespread damage (MMIVIII) to stone components of wooden buildings in the sparsely populated region of Nordland Norway, as well as very extensive rockfalls, liquefaction phenomena and a remarkable variety of disturbances in fjords and in the sea. The earthquake was felt throughout northern Scandinavia over distances of up to 800 km.

Ameloblastic fibrosarcoma

Ameloblastic fibrosarcoma is an extremely rare tumor. To date only 43 cases have been reported in the literature. An additional case of ameloblastic fibrosarcoma is presented; the clinical features, histologic characteristics, treatment, and the relevance of the presence of dental hard tissue are discussed.

1.06-microm laser damage of thin film optical coatings: a round-robin experiment involving various pulse lengths and beam diameters

A number of commercially available optical coatings, both antireflective and high reflective, have been tested for their laser-induced damage threshold, involving a total of eight different laboratories. The results obtained and the experimental methods used at these laboratories were discussed among the participants in this round robin at a minisymposium held at Balzers, Liechtenstein, 9-10 Dec. 1982. A final report of the round robin and a summary of the conclusions drawn at that symposium are presented.