An approach to software cost estimation

A general procedure for software cost estimation in any environment is outlined. The basic concepts of work and effort estimation are explained, some popular resource estimation models are reviewed, and the accuracy of source estimates is discussed. A software cost prediction procedure based on the experiences of the Software Engineering Laboratory in the flight dynamics area and incorporating management expertise, cost models, and historical data is described. The sources of information and relevant parameters available during each phase of the software life cycle are identified. The methodology suggested incorporates these elements into a customized management tool for software cost prediction. Detailed guidelines for estimation in the flight dynamics environment developed using this methodology are presented

Berom cultural beliefs and attitudes towards mental health problems in Nigeria: a mixed-methods study

Beliefs and attitudes are essential in mental health discourse. However, cultural beliefs and attitudes towards mental health problems (ATMHPs) among the Berom people of Nigeria are under-researched. The present studies made original contributions using the Cultural Identity Model (CIM) as predictors to investigate ATMHPs, and semi-structured interviews to further explain the potential impact of cultural beliefs on MHPs. In study-1, N = 140 participants responded to questionnaires on ATMHPs and were analysed using multivariate multiple regression in RStudio. Study-2 interviewed N = 13 participants (n = 7 laypeople; n = 6 practitioners). Interviews were recorded, transcribed and analysed thematically. Study-1 findings showed CIM as a non-significant predictor of ATMHPs. However, in study-2, four themes emerged: Cultural beliefs that MHPs are caused by spiritual forces; Berom indigenous preference for traditional healing; Christian religious healing in Berom communities; and Western-trained mental health practitioners' perception of lay service-users. The authors concluded that the Berom traditional and Christian religious healings are beneficial

The effect of perceived appearance judgements on psychological and biological stress processes across adulthood

Social self-preservation theory posits that stress is experienced when an aspect of an individual's identity has the potential to be negatively evaluated. Appearance is a central part of identity; however, little research has examined whether perceived appearance judgements are a source of social-evaluative stress. In addition, stress may be an explanatory link in the association between appearance perceptions and depressive symptoms. This study examined whether perceived appearance judgements were associated with increased stress and greater depressive symptoms among adults. Study 1 examined the associations between self-reported appearance judgements and cortisol stress responses in response to a laboratory stressor (Trier Social Stress Test) among 71 individuals aged 18–65. Study 2 assessed self-reported appearance judgements and depressive symptoms among 498 adults ages 18–65 via an online survey data collection. Appearance judgement was associated with a stronger cortisol response, higher self-reported stress, and greater depressive symptoms. Stress mediated all associations between appearance judgements and depressive symptoms and neither age nor gender moderated these associations. The findings suggest that appearance judgements contribute to psychological and biological stress processes and demonstrated that stress mediated the association between appearance judgements and depressive symptoms

Fast evaluation of appointment schedules for outpatients in health care

We consider the problem of evaluating an appointment schedule for outpatients in a hospital. Given a fixed-length session during which a physician sees K patients, each patient has to be given an appointment time during this session in advance. When a patient arrives on its appointment, the consultations of the previous patients are either already finished or are still going on, which respectively means that the physician has been standing idle or that the patient has to wait, both of which are undesirable. Optimising a schedule according to performance criteria such as patient waiting times, physician idle times, session overtime, etc. usually requires a heuristic search method involving a huge number of repeated schedule evaluations. Hence, the aim of our evaluation approach is to obtain accurate predictions as fast as possible, i.e. at a very low computational cost. This is achieved by (1) using Lindley's recursion to allow for explicit expressions and (2) choosing a discrete-time (slotted) setting to make those expression easy to compute. We assume general, possibly distinct, distributions for the patient's consultation times, which allows us to account for multiple treatment types, as well as patient no-shows. The moments of waiting and idle times are obtained. For each slot, we also calculate the moments of waiting and idle time of an additional patient, should it be appointed to that slot. As we demonstrate, a graphical representation of these quantities can be used to assist a sequential scheduling strategy, as often used in practice

Repair of Oronasal Fistulae by Interposition of Multilayered Amniotic Membrane Allograft

Background: Oronasal fistulas are a frequent complication after cleft palate surgery. Numerous repair methods have been described, but wound-healing problems occur often. The authors investigated, for the first time, the suitability of multilayered amniotic membrane allograft for fistula repair in a laboratory experiment (part A), a swine model (part B), and an initial patient series (part C). Methods: In part A, one-, two-, and four-layer porcine and human amniotic membranes (n = 20 each) were fixed in a digital towing device and the force needed for rupture was determined. In part B, iatrogenic oronasal fistulas in 18 piglets were repaired with amniotic membrane allograft, autofetal amniotic membrane, or small intestinal submucosa (n = 6 each). Healing was evaluated by probing and visual inflammation control (no/moderate/strong) on postoperative days 3, 7, 10, and 76. Histological analysis was performed to visualize tissue architecture. In part C, four patients (two women and two men, ages 21 to 51 years) were treated with multilayered amniotic membrane allograft. Results: In part A, forces needed for amniotic membrane rupture increased with additional layers (p < 0.001). Human amniotic membrane was stronger than porcine membrane (p < 0.001). In part B, fistula closure succeeded in all animals treated with amniotic membrane with less inflammation than in the small intestinal submucosa group. One fistula remained persistent in the small intestinal submucosa group. In part C, all fistulas healed completely without inflammation. Conclusions: Amniotic membrane is an easily available biomaterial and can be used successfully for oronasal fistula repair. The multilayer technique and protective plates should be utilized to prevent membrane ruptures

Percutaneous Anorectoplasty (PARP)-An Adaptable, Minimal-Invasive Technique for Anorectal Malformation Repair

Background: Anorectal malformations comprise a broad spectrum of disease. We developed a percutaneous anorectoplasty (PARP) technique as a minimal-invasive option for repair of amenable types of lesions. Methods: Patients who underwent PARP at five institutions from 2008 through 2021 were retrospectively analyzed. Demographic information, details of the operative procedure, and perioperative complications and outcomes were collected. Results: A total of 10 patients underwent the PARP procedure during the study interval. Patients either had low perineal malformations or no appreciable fistula. Most procedures were guided by ultrasound, fluoroscopy, or endoscopy. Median age at PARP was 3 days (range 1 to 311) days;eight patients were male. Only one intraoperative complication occurred, prompting conversion to posterior sagittal anorectoplasty. Functional outcomes in most children were highly satisfactory in terms of continence and functionality. Conclusions: The PARP technique is an excellent minimal-invasive alternative for boys born with perineal fistulae, as well as patients of both sexes without fistulae. The optimal type of guidance (ultrasound, fluoroscopy, or endoscopy) depends on the anatomy of the lesion and the presence of a colostomy at the time of repair

A family of diameter-based eigenvalue bounds for quantum graphs

We establish a sharp lower bound on the first non-trivial eigenvalue of the Laplacian on a metric graph equipped with natural (i.e., continuity and Kirchhoff) vertex conditions in terms of the diameter and the total length of the graph. This extends a result of, and resolves an open problem from, [J. B. Kennedy, P. Kurasov, G. Malenov\'a and D. Mugnolo, Ann. Henri Poincar\'e 17 (2016), 2439--2473, Section 7.2], and also complements an analogous lower bound for the corresponding eigenvalue of the combinatorial Laplacian on a discrete graph. We also give a family of corresponding lower bounds for the higher eigenvalues under the assumption that the total length of the graph is sufficiently large compared with its diameter. These inequalities are sharp in the case of trees.Comment: Substantial revision of v1. The main result, originally for the first eigenvalue, has been generalised to the higher ones. The title has been changed and the proofs substantially reorganised to reflect the new result, and a section containing concluding remarks has been adde

Daily life stress and the cortisol awakening response : testing the anticipation hypothesis

Acknowledgments We thank Paul Stewart for his contribution to data collection and Dr Matthew Jones for programming the handheld computers. Author Contributions Conceived and designed the experiments: WS DJP. Performed the experiments: DJP. Analyzed the data: WS. Wrote the paper: WS DJP.Peer reviewedPublisher PD