Medical and surgical management of pneumothorax in diving and hyperbaric chambers.

The presence of a pneumothorax within a pressurized chamber represents unique diagnostic and management challenges. This is particularly the case in the medical and geographic remoteness of many chamber locations. Upon commencing chamber decompression, unvented intrapleural air expands. If its initial volume and/or degree of chamber pressure reduction is significant enough, a tension pneumothorax will result. Numerous reports chronicle failure to diagnose and manage in-chamber pneumothorax with resultant morbidity and one fatal outcome. Such cases have occurred in both medically remote and clinically based settings. This paper reviews pneumothorax and tension pneumothorax risk factors and clinical characteristics. It suggests primary medical management using the principle of oxygen-induced inherent unsaturation in concert with titrated chamber decompression designed to prevent intrapleural air expanding faster than it contracts. Should this conservative approach prove unsuccessful, and surgical venting becomes necessary or otherwise immediately indicated, interventional options are reviewed.

Pneumothorax during manned chamber operations: A summary of reported cases.

In-chamber pneumothorax has complicated medically remote professional diving operations, submarine escape training, management of decompression illness, and hospital-based provision of hyperbaric oxygen therapy. Attempts to avoid thoracotomy by combination of high oxygen partial pressure breathing (the concept of inherent unsaturation) and greatly slowed rates of chamber decompression proved successful on several occasions. When this delicate balance designed to prevent the intrapleural gas volume from expanding faster than it contracts proved futile, chest drains were inserted. The presence of pneumothorax was misdiagnosed or missed altogether with disturbing frequency, resulting in wide-ranging clinical consequences. One patient succumbed before the chamber had been fully decompressed. Another was able to ambulate unaided from the chamber before being diagnosed and managed conventionally. In between these two extremes, patients experienced varying degrees of clinical compromise, from respiratory distress to cardiopulmonary arrest, with successful resuscitation. Pneumothorax associated with manned chamber operations is commonly considered to develop while the patient is under pressure and manifests during ascent. However, published reports suggest that many were pre-existing prior to chamber entry. Risk factors included pulmonary barotrauma-induced cerebral arterial gas embolism, cardiopulmonary resuscitation, and medical or surgical procedures usually involving the lung. This latter category is of heightened importance to hyperbaric operations as an iatrogenically induced pneumothorax may take as long as 24 hours to be detected, perhaps long after a patient has been cleared for chamber exposure.

Relative energy deficiency in dance (RED-D): a consensus method approach to REDs in dance.

Relative energy deficiency in sport (REDs) is a potentially severe, challenging, broad-spectrum syndrome with potential negative health and performance outcomes. The numerous research publications and International Olympic Committee consensus statements relating to REDs testify to the challenges faced in early identification or screening, diagnosis and management. Like sport, dance, in its simplest form, can be identified as an activity resulting in physiological energy demands and, as such, requires appropriate energy availability concerning energy expenditures. However, the specificity of physiological and psychological demands in dance must be considered when considering REDs. An environment where physical activity can exceed 30 hours per week and where culture may instil a value that thinness is required puts dancers at increased risk for REDs. The purpose of this study was to provide dance-specific guidance dance on this complex condition. An RAND/UCLA Delphi Panel method with nominal group technique was used to review the literature from REDs to evaluate how it may relate to dance. In addition to the EP, which was assembled from a multidisciplinary background with expertise in REDs and multiple genres of dance, six focus groups were commissioned. Four of the focus groups were drawn from the EP members and two additional focus groups formed by dancers and artistic leaders. These panels were used to guide the development of a RED-D diagnosis pathway, management plan and risk stratification and return to dance pathway. The dance-specific pathways are designed to be a practical tool for guiding and supporting clinicians managing RED-D. Furthermore, this paper represents an important focus of this area in dance and serves to stimulate discussion and further research within the sector.

Evaluation of multi-directional speed qualities throughout adolescence in youth soccer: The non-linear nature of transfer.

Training and assessment of agility is often prioritised by soccer coaches and practitioners aiming to develop multi-directional speed. Although the importance of agility is advocated throughout childhood and adolescence, limited data evidence agility performance at different stages of adolescence. The purpose of this study was to examine differences in multi-directional speed performance in youth soccer players spanning an entire soccer academy. A total of 86 male junior-elite soccer players volunteered to participate. Anthropometric data were collected, alongside performance data from a battery of physical tests including sprinting, jumping, change of direction, reaction time, and agility. Bayesian models using log-likelihoods from posterior simulations of parameter values displayed linear or curvilinear relationships between both chronological and biological age and performance in all tests other than agility and reaction time. For agility and reaction time tests, performance improved until ~14 years of age or the estimated age of peak height velocity whereby arrested development in performance was observed. Our results demonstrate that while most performance skills improve as chronological or biological age increases, measures of agility and reaction time may not. These findings support the notion that agility performance is complex and multifaceted, eliciting unique, challenging physical demands and non-linear development.

Pilot randomized controlled trial of biofeedback on reducing psychological and physiological stress among persons experiencing homelessness.

People experiencing homelessness report increased exposure to traumatic life events and higher rates of depression, anxiety, and post-traumatic stress disorder as compared with the general population. Heart rate variability-biofeedback (HRV-BF) has been shown to decrease symptoms of stress, anxiety, depression, and PTSD. However, HRV-BF has not been tested with the most vulnerable of populations, homeless adults. The purpose of this randomized controlled trial was to compare the effectiveness of an HRV-BF intervention versus a Health Promotion (HP) active control intervention focused on improving mental health symptoms among homeless adults. Guided by a community advisory board, homeless adults residing in Skid Row, Los Angeles (n = 40) were randomized to either the HRV-BF or an active HP control group and received eight weekly, 30-min sessions over two months, delivered by a nurse-led community health worker team. Dependent variables of HRV, mental health, anxiety, depression, and PTSD were measured at baseline, the 8-week session, and/or 2-month follow-up. All intervention sessions were completed by 90% (36/40) of participants. Both the HRV-BF and HP interventions showed significant increases in HRV from baseline to 2-month follow-up, with no significant difference between the intervention groups. The HRV-BF programme revealed a somewhat greater, although non-significant, improvement in anxiety, depression, and PTSD symptoms than the HP programme. The usefulness of both interventions, focused on emotional and physical health, warrants future studies to examine the value of a combined HRV-BF and HP intervention.

Highlighter: An optogenetic system for high-resolution gene expression control in plants.

Optogenetic actuators have revolutionized the resolution at which biological processes can be controlled. In plants, deployment of optogenetics is challenging due to the need for these light-responsive systems to function in the context of horticultural light environments. Furthermore, many available optogenetic actuators are based on plant photoreceptors that might crosstalk with endogenous signaling processes, while others depend on exogenously supplied cofactors. To overcome such challenges, we have developed Highlighter, a synthetic, light-gated gene expression system tailored for in planta function. Highlighter is based on the photoswitchable CcaS-CcaR system from cyanobacteria and is repurposed for plants as a fully genetically encoded system. Analysis of a re-engineered CcaS in Escherichia coli demonstrated green/red photoswitching with phytochromobilin, a chromophore endogenous to plants, but also revealed a blue light response likely derived from a flavin-binding LOV-like domain. We deployed Highlighter in transiently transformed Nicotiana benthamiana for optogenetic control of fluorescent protein expression. Using light to guide differential fluorescent protein expression in nuclei of neighboring cells, we demonstrate unprecedented spatiotemporal control of target gene expression. We implemented the system to demonstrate optogenetic control over plant immunity and pigment production through modulation of the spectral composition of broadband visible (white) light. Highlighter is a step forward for optogenetics in plants and a technology for high-resolution gene induction that will advance fundamental plant biology and provide new opportunities for crop improvement.

Exploratory assessment: Nurse-led community health worker delivered HCV intervention for people experiencing homelessness.

BACKGROUND: Getting and maintaining Hepatitis C Virus (HCV) cure is challenging among people experiencing homelessness (PEH) as a result of critical social determinants of health such as unstable housing, mental health disorders, and drug and alcohol use. OBJECTIVES: The purpose of this exploratory pilot study was to compare a registered nurse/community health worker (RN/CHW)-led HCV intervention tailored for PEH, "I am HCV Free," with a clinic-based standard of care (cbSOC) for treating HCV. Efficacy was measured by sustained virological response at 12 weeks after stopping antivirals (SVR12), and improvement in mental health, drug and alcohol use, and access to healthcare. METHODS: An exploratory randomized controlled trial design was used to assign PEH recruited from partner sites in the Skid Row Area of Los Angeles, California, to the RN/CHW or cbSOC programs. All received direct-acting antivirals. The RN/CHW group received directly observed therapy in community-based settings, incentives for taking HCV medications, and wrap-around services, including connection to additional healthcare services, housing support, and referral to other community services. For all PEH, drug and alcohol use and mental health symptoms were measured at month 2 or 3 and 5 or 6 follow-up, depending on HCV medication type, while SVR12 was measured at month 5 or 6 follow-up. RESULTS: Among PEH in the RN/CHW group, 75% (3 of 4) completed SVR12 and all three attained undetectable viral load. This was compared with 66.7% (n = 4 of 6) of the cbSOC group who completed SVR12; all four attained undetectable viral load. The RN/CHW group, as compared to the cbSOC, also showed greater improvements in mental health, and significant improvement in drug use, and access to healthcare services. DISCUSSION: While this study shows significant improvements in drug use and health service access among the RN/-CHW group, the sample size of the study limits the validity and generalizability of the results. Further studies using larger sample sizes are necessitated.

Non-pharmaceutical interventions and risk of COVID-19 infection: survey of U.K. public from November 2020 - May 2021.

INTRODUCTION: Non-pharmaceutical interventions (NPIs), such as handwashing, social distancing and face mask wearing, have been widely promoted to reduce the spread of COVID-19. This study aimed to explore the relationship between self-reported use of NPIs and COVID-19 infection. METHODS: We conducted an online questionnaire study recruiting members of the UK public from November 2020 to May 2021. The association between self-reported COVID-19 illness and reported use of NPIs was explored using logistic regression and controlling for participant characteristics, month of questionnaire completion, and vaccine status. Participants who had been exposed to COVID-19 in their household in the previous 2 weeks were excluded. RESULTS: Twenty-seven thousand seven hundred fifty-eight participants were included and 2,814 (10.1%) reported having a COVID-19 infection. The odds of COVID-19 infection were reduced with use of a face covering in unadjusted (OR 0.17 (95% CI: 0.15 to 0.20) and adjusted (aOR 0.19, 95% CI 0.16 to 0.23) analyses. Social distancing (OR 0.27, 95% CI: 0.22 to 0.31; aOR 0.35, 95% CI 0.28 to 0.43) and handwashing when arriving home (OR 0.57, 95% CI 0.46 to 0.73; aOR 0.63, 95% CI: 0.48 to 0.83) also reduced the odds of COVID-19. Being in crowded places of 10-100 people (OR 1.89, 95% CI: 1.70 to 2.11; aOR 1.62, 95% CI: 1.42 to 1.85) and > 100 people (OR 2.33, 95% CI: 2.11 to 2.58; aOR 1.73, 95% CI: 1.53 to 1.97) were both associated with increased odds of COVID-19 infection. Handwashing before eating, avoiding touching the face, and cleaning things with virus on were all associated with increased odds of COVID-19 infections. CONCLUSIONS: This large observational study found evidence for strong protective effects for individuals from use of face coverings, social distancing (including avoiding crowded places) and handwashing on arriving home on developing COVID-19 infection. We also found evidence for an increased risk associated with other behaviours, possibly from recall bias.

COVID-19 vaccination beliefs, attitudes, and behaviours among health and social care workers in the UK: A mixed-methods study.

BACKGROUND: The UK began delivering its COVID-19 vaccination programme on 8 December 2020, with health and social care workers (H&SCWs) given high priority for vaccination. Despite well-documented occupational exposure risks, however, there is evidence of lower uptake among some H&SCW groups. METHODS: We used a mixed-methods approach-involving an online cross-sectional survey and semi-structured interviews-to gain insight into COVID-19 vaccination beliefs, attitudes, and behaviours amongst H&SCWs in the UK by socio-demographic and employment variables. 1917 people were surveyed- 1656 healthcare workers (HCWs) and 261 social care workers (SCWs). Twenty participants were interviewed. FINDINGS: Workplace factors contributed to vaccination access and uptake. SCWs were more likely to not be offered COVID-19 vaccination than HCWs (OR:1.453, 95%CI: 1.244-1.696). SCWs specifically reported uncertainties around how to access COVID-19 vaccination. Participants who indicated stronger agreement with the statement 'I would recommend my organisation as a place to work' were more likely to have been offered COVID-19 vaccination (OR:1.285, 95%CI: 1.056-1.563). Those who agreed more strongly with the statement 'I feel/felt under pressure from my employer to get a COVID-19 vaccine' were more likely to have declined vaccination (OR:1.751, 95%CI: 1.271-2.413). Interviewees that experienced employer pressure to get vaccinated felt this exacerbated their vaccine concerns and increased distrust. In comparison to White British and White Irish participants, Black African and Mixed Black African participants were more likely to not be offered (OR:2.011, 95%CI: 1.026-3.943) and more likely to have declined COVID-19 vaccination (OR:5.550, 95%CI: 2.294-13.428). Reasons for declining vaccination among Black African participants included distrust in COVID-19 vaccination, healthcare providers, and policymakers. CONCLUSION: H&SCW employers are in a pivotal position to facilitate COVID-19 vaccination access, by ensuring staff are aware of how to get vaccinated and promoting a workplace environment in which vaccination decisions are informed and voluntary.

The Deceleration Deficit: A Novel Field-Based Method to Quantify Deceleration During Change of Direction Performance.

ABSTRACT: Clarke, R, Read, PJ, De Ste Croix, MBA, and Hughes, JD. The deceleration deficit: a novel field-based method to quantify deceleration during change of direction performance. J Strength Cond Res 36(9): 2434-2439, 2022-The study investigated the relationship between linear and change of direction (COD) speed performance components and the individual differences between deceleration deficit (DD) and COD deficit (CODD). Thirty-six subjects (mean ± SD : age = 20.3 ± 2.9 years; stature = 175.2 ± 7.7 cm; and body mass = 78.0 ± 16.7 kg) completed 3 trials of a 505 test in both turning directions (dominant [D]; nondominant [ND]) and 3 15-m linear sprints. Deceleration deficit was calculated by the 15-m approach in the 505 test, minus the athlete's linear 15-m sprint time. To compare individuals CODD and DD, z-scores were calculated, and moderate worthwhile changes (MWCs) were identified between these deficit z-scores. Significant correlations were identified between linear sprints and 505 time (D: r = 0.71, 0.74; P < 0.01. ND: r = 0.76, 0.75; P < 0.01) for 10-m and 15-m sprint. respectively, and between 505 performance and CODD (D: r = 0.74; P < 0.01. ND: r = 0.77; P < 0.01) and DD (D: r = 0.41, P < 0.05. ND: r = 0.44, P < 0.01). Deceleration deficit was significantly related to CODD (D: r = 0.59; P < 0.01. ND: r = 0.62; P < 0.01); however, 78% of subjects demonstrated differences between these deficit measures greater than an MWC. In conclusion, linear speed has the strongest significant relationship with 505 performance. Deceleration deficit could provide a more isolated construct than CODD which may be related to an athlete's deceleration capabilities.

Lurasidone for Adolescents With Complex Mental Disorders: A Case Series.

OBJECTIVES: Lurasidone is a new second generation (atypical) antipsychotic agent with unique receptor affinity and side-effect profiles, but limited literature is available on its use in adolescent populations. Contrasting with research treatment trials which typically recruit patients by stringent selection criteria, this case series examined the effects and tolerability of using lurasidone in adolescents within real-life clinical settings in treating complex cases who had not responded to other therapy options. METHODS: We conducted a retrospective case-note audit of 6 adolescents aged 14 to 17 years old attending community child and adolescent mental health services (CAMHS) who were prescribed lurasidone. RESULTS: Lurasidone had been prescribed for a range of "hard-to-manage" conditions with complex comorbidities, in adolescents in relation to specific use of lurasidone on the basis of clinical and pharmacological indications after exhausting more conventional treatment options. Case-note review suggested response to lurasidone was clinically positive in 3 cases, equivocal/marginal in 2 cases, and ineffective in 1 case. There were no cases of poor tolerance or adverse effects. Notably, positive responses for depressive and irritable mood symptoms were specifically recorded by prescribing clinicians, indicative of benefits on symptom improvement. No lurasidone attributed weight gain, galactorrhoea, metabolic abnormalities, sexual dysfunction or intolerance were reported. Pro-cognitive effects were not detected; but our findings were constrained by the non-systematic and incomplete information ascertainment, typical in retrospective case-note review. CONCLUSION: This case series provides preliminary data supporting lurasidone's potential use in adolescents of complex clinical needs (but without a clinical diagnosis of bipolar disorder) within real-life clinical settings. Lurasidone appears to show a weight-sparing effect, in addition to improving mood symptoms in some cases. Lurasidone deserves further study for its use in the adolescent population (outside the remit of FDA) given its potential more favorable risk-benefit profile in young people. The favorable tolerability appear to be borne out by the pharmacodynamic predictions in our complex patients who would be excluded in formal clinical trial studies.

Theory of cell membrane interaction with glass.

There are three regimes of cell membrane interaction with glass: Tight and loose adhesion, separated by repulsion. Explicitly including hydration, this paper evaluates the pressure between the surfaces as functions of distance for ion correlation and ion-screened electrostatics and electromagnetic fluctuations. The results agree with data for tight adhesion energy (0.5-3 vs 0.4-4 mJ/m^{2}), detachment pressure (7.9 vs. 9 MPa), and peak repulsion (3.4-7.5 vs. 5-10 kPa), also matching the repulsion's distance dependence on renormalization by steric pressure mainly from undulations.

Change-of-Direction Deficit vs. Deceleration Deficit: A Comparison of Limb Dominance and Inter-limb Asymmetry between Forwards and Backs in Elite Male Rugby Union Players.

The aims of the present study were to: 1) determine whether limb dominance and inter-limb asymmetry were the same across both change of direction (COD) and deceleration (DEC) deficits and, 2) determine the association between the COD and DEC-deficits and other physical performance tests in elite male rugby union players. Twenty five players performed a series of bilateral jumps, linear and COD speed tests at the end of the pre-season period. COD and DEC-deficits were calculated for both left and right sides, and inter-limb asymmetry thereafter. Kappa coefficients revealed moderate levels of agreement in limb dominance between COD and DEC-deficits (Kappa = 0.41 on left; 0.48 on right). For the direction of asymmetry, perfect levels of agreement (Kappa = 1) were evident between 505 time and COD-deficit, but only moderate levels of agreement (Kappa = 0.41) between other asymmetry measures. Pearson's r correlations showed moderate to large relationships between jumps and linear (r = -0.42 to -0.68) and COD speed (r = -0.41 to -0.58), but not with the COD-deficit (r = 0.15 to -0.31), DEC-deficit (r = 0.01 to -0.32) or asymmetry (r = 0.16 to -0.29). When analysing by playing position, backs were significantly faster than forwards over 15-m (ES = -0.86) and across all jump tests (ES = 0.86-0.94), with the exception of the squat jump. This study is the first to provide a direct comparison of the COD and DEC-deficits and highlights that limb dominance and asymmetry cannot be guaranteed between tasks.

Parents' and guardians' views and experiences of accessing routine childhood vaccinations during the coronavirus (COVID-19) pandemic: A mixed methods study in England.

OBJECTIVE: To explore parents' and guardians' views and experiences of accessing National Health Service (NHS) general practices for routine childhood vaccinations during the coronavirus (COVID-19) pandemic in England. DESIGN: Mixed methods approach involving an online cross-sectional survey (conducted between 19th April and 11th May 2020) and semi-structured telephone interviews (conducted between 27th April and 27th May 2020). PARTICIPANTS: 1252 parents and guardians (aged 16+ years) who reported living in England with a child aged 18 months or under completed the survey. Nineteen survey respondents took part in follow-up interviews. RESULTS: The majority of survey respondents (85.7%) considered it important for their children to receive routine vaccinations on schedule during the COVID-19 pandemic; however, several barriers to vaccination were identified. These included a lack of clarity around whether vaccination services were operating as usual, particularly amongst respondents from lower income households and those self-reporting as Black, Asian, Chinese, Mixed or Other ethnicity; difficulties in organising vaccination appointments; and fears around contracting COVID-19 while attending general practice. Concerns about catching COVID-19 while accessing general practice were weighed against concerns about children acquiring a vaccine-preventable disease if they did not receive scheduled routine childhood vaccinations. Many parents and guardians felt their child's risk of acquiring a vaccine-preventable disease was low as the implementation of stringent physical distancing measures (from March 23rd 2020) meant they were not mixing with others. CONCLUSION: To promote routine childhood vaccination uptake during the current COVID-19 outbreak, further waves of COVID-19 infection, and future pandemics, prompt and sustained national and general practice level communication is needed to raise awareness of vaccination service continuation and the importance of timely vaccination, and invitation-reminder systems for vaccination need to be maintained. To allay concerns about the safety of accessing general practice, practices should communicate the measures being implemented to prevent COVID-19 transmission.

Parents' and guardians' views on the acceptability of a future COVID-19 vaccine: A multi-methods study in England.

BACKGROUND: The availability of a COVID-19 vaccine has been heralded as key to controlling the COVID-19 pandemic. COVID-19 vaccination programme success will rely on public willingness to be vaccinated. METHODS: We used a multi-methods approach - involving an online cross-sectional survey and semi-structured interviews - to investigate parents' and guardians' views on the acceptability of a future COVID-19 vaccine. 1252 parents and guardians (aged 16 + years) who reported living in England with a child aged 18 months or under completed the survey. Nineteen survey participants were interviewed. FINDINGS: Most survey participants reported they would likely accept a COVID-19 vaccine for themselves (Definitely 55.8%; Unsure but leaning towards yes 34.3%) and their child/children (Definitely 48.2%; Unsure but leaning towards yes 40.9%). Less than 4% of survey participants reported that they would definitely not accept a COVID-19 vaccine. Survey participants were more likely to accept a COVID-19 vaccine for themselves than their child/children. Participants that self-reported as Black, Asian, Chinese, Mixed or Other ethnicity were almost 3 times more likely to reject a COVID-19 vaccine for themselves and their children than White British, White Irish and White Other participants. Survey participants from lower-income households were also more likely to reject a COVID-19 vaccine. In open-text survey responses and interviews, self-protection from COVID-19 was reported as the main reason for vaccine acceptance. Common concerns identified in open-text responses and interviews were around COVID-19 vaccine safety and effectiveness, mostly prompted by the newness and rapid development of the vaccine. CONCLUSION: Information on how COVID-19 vaccines are developed and tested, including their safety and efficacy, must be communicated clearly to the public. To prevent inequalities in uptake, it is crucial to understand and address factors that may affect COVID-19 vaccine acceptability in ethnic minority and lower-income groups who are disproportionately affected by COVID-19.

Monoplace chamber treatment of decompression illness: Review and commentary.

This paper summarises the history and capabilities of monoplace chambers in treatment of decompression illness (DCI); both in support of diving operations and in the hospital setting. In the field, monoplace hyperbaric chambers provide victims of DCI immediate access to recompression in settings where traditional multiplace chambers are not available. Alternatively, they may facilitate pressurised transport to a multiplace chamber for continued management. Recently, collapsible lightweight versions have improved suitability for field deployment aboard small vessels in remote settings, and for use by less technically capable military, occupational and civilian operators. The resulting elimination of treatment delays may prove lifesaving and central nervous system sparing, and avoid subsequent diving fitness disqualification. Monoplace chambers thus facilitate diving operations that would otherwise be difficult to condone on health and safety grounds. The 1960s saw the introduction of multiplace hyperbaric chambers into the hospital setting, as a number of non-diving conditions appeared to benefit from hyperbaric oxygen. This coincided with interest in hyperbaric oxygen as a solid tumour radiation sensitiser. Development of a novel acrylic-hulled single occupancy chamber enabled patients to undergo radiotherapy while pressurised within its oxygen atmosphere. Increasing numbers of health care facilities adopted this chamber type as a more economical, less complex alternative to the multiplace chamber. Incorporation of relevant biomedical technologies have allowed monoplace chambers to support increasingly complex patients in a safe, effective manner. Despite these advances, criticism of medical centre-based monoplace chamber treatment of DCI exists. This paper evaluates this controversy and presents relevant counter-arguments.

A coupled one dimension and transmission line model for arterial flow simulation.

A broad choice of numerical schemes and methods currently exists for blood flow simulations. The results rely critically on the prescription of boundary conditions. The outflow boundary condition for a one-dimensional (1D) flow solver is usually prescribed via a Windkessel or lumped parameter model. The weakness of such an approach is the determination of the parameters. In the present work, we use an alternative approach, that is, a reflection coefficient (RC), to lumped parameter models for distal boundary conditions. With such a RC, the number of parameters required is reduced to one. We derive the theoretical foundation for the RC. Specifically, we couple a transmission line theory for peripheral resistance with a 1D arterial flow solver. We apply this method to a healthy and a stenosed virtual aorta, and show this method can reproduce some subtle features in arterial pressure propagation, such as the steepened pressure waveform and the reflection from the stenosed site. In summary, the RC parameter has strong physical implications in the theory of wave propagation and may be used in flow simulations where reflections need to be explicitly modeled. NOVELTY STATEMENT: A novel coupled one-dimensional-transimission line model has been developed in this work with detailed implementations. Only one outflow boundary condition, that is, the refection coefficient is required in the model. Reflections for a pulse wave from aortic terminals as well as from a stenotic site are numerically simulated.