Outflow Index Research Articles

Optimizing Hospital Bed Capacity and Resource Allocation Using Inflow and Outflow Indices for Effective Healthcare Management.

This study analyzes hospital bed capacity and resource allocation using inflow and outflow indices to identify disparities in bed utilization. The COVID-19 pandemic highlighted the need for effective healthcare management, particularly in the allocation of specialized beds such as those in intensive care units (ICU). Despite a high bed-to-population ratio, South Korea faces regional disparities in bed distribution, especially in Seoul, which accounts for 12.4% of the nation's hospital beds. Hospital beds were categorized based on the Medical Service Act, and the Relevance Index (RI) and Commitment Index (CI) were used to assess patient flow in 2019 across different bed types and functions. Data from the "Statistical Yearbook on the Usage of Medical Service by Region" provided insights into utilization patterns in tertiary referral hospitals, general hospitals, hospitals, and long-term care facilities. The analysis revealed high RIs for tertiary referral hospitals, indicating strong patient retention and minimal outflow, whereas lower RIs for long-term care hospitals suggested underutilization. Regional analysis within Seoul found a concentration of tertiary referral hospitals in the Southeast and a shortage of ICU beds in the Northwest and Southwest regions. The Inflow and Outflow Index confirmed significant patient inflow into tertiary referral hospitals, with some areas experiencing higher outflows, particularly for long-term care beds. These findings underscore the need for strategic hospital bed capacity management, prioritizing essential beds in underserved regions. Future research should incorporate more recent data and employ direct patient flow analysis to optimize resource allocation, addressing evolving healthcare demands, such as an aging population and new infectious diseases. This study offers valuable insights for regional health policy, aiming to enhance functional hospital bed management and improve overall healthcare resource utilization.

Impact of Oral Habits and Buccal Frenulum on Gingival Microcirculation in Children: Findings and Clinical Significance

Background. Oral mucosal abnormalities such as abnormal lip frenulum, buccal frenulum, ankyloglossia are commonly observed in a routine dental practice. The close anatomical and functional relationship between the gingiva and the alveolar bone determines the significance of abnormal mucosal structures in the development of malocclusions and periodontal diseases. Oral habits are more prevalent in childhood; however, they can persist into adolescence and adulthood, potentially leading to dentofacial impairments and malocclusions. Therefore, there is a growing interest in understanding oral mucosal blood flow in the presence of oral habits and abnormal mucosal structures, as their combined effects may have a synergistic influence on the development of maxillomandibular anomalies.
 Aim. This study was aimed to investigate age-depended parameters of gingival microcirculation in children with buccal frenulum, oral habits, and maxillomandibular anomalies.
 Methods. This cross-sectional study involved 45 apparently healthy children and 180 children with oral habits, buccal frenulum, and maxillomandibular anomalies, divided into 3 age groups (ages 9 to 12, 12 to 15, and 15 to 17 years). Oral mucosal blood flow was assessed using a rheograph DX (Kharkiv, Ukraine) by measuring qualitative characteristics and quantitative parameters such as the vascular tone index (VTI), venous outflow index (VOI), peripheral resistance index (PRI), extensive blood flow index (EBFI), and rheographic index (RI). Statistical analysis included Spearman’s correlation, a Kruskal-Wallis H test, and a Dunn’s post-hoc test.
 Results. The study revealed a significantly higher VTI in all patient groups, increasing with age and reaching +80.54% in the oldest age group compared to the respective control group. This elevation was accompanied by a moderate correlation enhancing the PRI (+4.61% in 9-12-year-old group to +33.42% in 15-17-year-old group). Furthermore, the VOI exhibited a noteworthy and age-dependent increase; however, there was a notable reduction in the RI (-41.10% to -59.70%) and EBFI values (-35.54% and -37.70% versus -23.97% in the youngest age group).
 Conclusions. This study demonstrated a relationship between oral habits, buccal frenulum, and age-dependent disturbance of gingival microcirculation in children. The findings suggest that chronic traumatization due to oral habits and abnormal mucosal structures lead to increased vasoconstriction and impaired vessel elasticity. Early intervention and management of such category of patients are crucial for preserving optimal gingival microcirculation.

Зміни кровопостачання тканин пародонта у пацієнтів із зубощелепними аномаліями на фоні порушень архітектоніки присінка рота на етапах комплексного лікування

The aim of the study. To study of the state of regional blood supply in the tissues of the vestibule of the mouth maxillomandibular anomalies on the background disorders of the architectonics of the vestibule of the mouth. Research methods. 60 patients with maxillomandibular anomalies and disorders of the architectonics of the vestibule of the mouth were examined and treated. The age group of patients is 15–17 years old. The first group consisted of 30 patients who had plastic surgery of connective strands by the classical method, where the wound was healed by secondary tension. In group 1A (15 people) in the postoperative period, chlorhexidine-denta was prescribed, in group 1B (15 people) – chlorhexidine-denta and gengigel. In the second group (30 patients), plastic surgery of connective strands were performed using our proposed method, where the wound heals by primary tension. In group 2A (15 people) in the postoperative period, chlorhexidine-denta was prescribed, in group 2B (15 people) – chlorhexidine-denta and gengigel. In comparison group where were 15 persons without maxillofacial anomalies, deformities, oral habits and periodontal status. All patients underwent rheography of the vestibule of the mouth with the help of the following devices and programs: Rheograph “DX”, “DX-Complex Regina 2002”. Rheoelectroencephalograph was a recording device. The study was conducted before treatment and after surgical correction (1 month, 6 months, 12 months). Scientific novelty. The results of investigation of regional circulation of the tissues of the vestibule of the mouth showed the presence of blood circulation deficit and reduce the trophic tissue, which was indicated by the increase in vascular tone index (VTI), venous outflow index (VOI), peripheral resistance index (PRI) and reduce of extensive blood flow index (EBFI) аnd rheographic index (RI) (p<0.05). Qualitative characteristics of rheograms were correlated with quantitative characteristics. After the treatment, positive dynamics of rheographic indicators were observed in all groups, however Conclusions. The results of the rheographic study in terms of quantitative and qualitative characteristics showed that patients with maxillomandibular anomalies and disorders of the architectonics of the vestibule of the mouth (15–17 years old) have pronounced stagnation in the periodontal tissues, insufficiency of blood circulation, and impaired venous outflow. Surgical correction by our proposed method using palatal mucosal grafts and gengigel in the postoperative period ensures normalization and stabilization of rheographic indicators in the early and longterm follow-up. Key words: vestibule of the mouth, buccal frenulum, periodontium, oral mucosa, allogeneic transplantation, blood supply.

Air plethysmography characteristic of the pathological segmental hypervolemia of the calf in patients with CVD clinical classes (CEAP)

Introduction. The involvement of pathological segmental venous hypervolemia of the lower leg in patients with varicose veins in the formation of chronic venous insufficiency (CVI) is an established fact, however, objective criteria for this pathohemodynamic phenomenon have not been definitively determined today.The purpose of the study. Determination by air plethysmography (APG) of the degree of functional disorders in the limb and establishment of significant criteria characterizing pathological segmental hypervolemia of the lower leg in patients with CVD of various clinical classes according to CEAP.Materials and methods. For the period from 2002 to 2019, 380 healthy individuals with no symptoms of chronic venous diseases and 896 patients with CVD were examined with the use of APG, with their distribution in accordance with the CEAR international classification as follows: C0–C1, C2–C3, C4–C6 clinical classes. To assess the intensity of venous blood flow, the following values were calculated: the maximum capacity of the leg veins (Venous Capacity – VC), the volume of their evacuation (Evacuation Volume – EV) for a set time, the maximum venous outflow (Maximum Venous Outflow – MVO), the ratio of these values on both limbs (Venous Capacity Index – VC1, Evacuation Volume Index – EVI, Maximum Venous Outflow Index – MVOI).Results. The most statistically significant and conjugate correlation data were obtained (expectation, mean square deviation, standard error of expectation, median and coefficient of variation) during the analysis in groups according to the characteristic VCI.Discussion. The obtained results allowed us to assert that APG is an informative functional method for diagnosing hemodynamic disorders in patients with lower limb CVD.Conclusion. The established criteria of the venous capacity index will allow in practice to give an objective characterization of the degree of change in hemodynamic disorders in patients with CVD before and after the treatment undertaken.

Apparent Seasonal Bias in Delta Outflow Estimates as Revealed in the Historical Salinity Record of the San Francisco Estuary: Implications for Delta Net Channel Depletion Estimates

Accurate estimates of freshwater flow to the San Francisco Estuary are important in successfully regulating this water body, in protecting its beneficial uses, and in accurately modeling its hydrodynamic and water-quality transport regime. For regulatory purposes, freshwater flow to the estuary is not directly measured; rather, it is estimated from a daily balance of upstream Delta inflows, exports, and in-Delta water use termed the net Delta outflow index (NDOI). Field research in the 1960s indicated that NDOI estimates are biased low in summer–fall and biased high in winter–spring as a result of conflating Delta island evapotranspiration estimates with the sum of ungauged hydrologic interactions between channels and islands referred to as net channel depletions. In this work, we employed a 50-year observed salinity record along with gauged tidal flows and an ensemble of five empirical flow-salinity (X2) models to test whether a seasonal bias in Delta outflow estimates could be inferred. We accomplished this objective by conducting statistical analyses and evaluating whether model skill could be improved through seasonal NDOI flow adjustments. Assuming that model residuals are associated with channel depletion uncertainty, our findings corroborate the 1960s research and suggest that channel depletions are biased low in winter months (i.e., NDOI is biased high) and biased high in late summer and early fall months (i.e., NDOI is biased low). The magnitude of seasonal bias, which can reach 1,000 cfs, is a small percentage of typical winter outflow but represents a significant percentage of typical summer outflow. Our findings were derived from five independently developed models, and are consistent with the physical understanding of water exchanges on the islands. This work provides motivation for improved characterization of these exchanges to improve Delta outflow estimates, particularly during drought periods when water supplies are scarce and must be carefully managed.

Hemodynamic Analysis of Cerebral AVMs with 3D Phase-Contrast MR Imaging.

The hemodynamics associated with cerebral AVMs have a significant impact on their clinical presentation. This study aimed to evaluate the hemodynamic features of AVMs using 3D phase-contrast MR imaging with dual velocity-encodings. Thirty-two patients with supratentorial AVMs who had not received any previous treatment and had undergone 3D phase-contrast MR imaging were included in this study. The nidus diameter and volume were measured for classification of AVMs (small, medium, or large). Flow parameters measured included apparent AVM inflow, AVM inflow index, apparent AVM outflow, AVM outflow index, and the apparent AVM inflow-to-outflow ratio. Correlation coefficients between the nidus volume and each flow were calculated. The flow parameters between small and other AVMs as well as between nonhemorrhagic and hemorrhagic AVMs were compared. Patients were divided into hemorrhagic (n = 8) and nonhemorrhagic (n = 24) groups. The correlation coefficient between the nidus volume and the apparent AVM inflow and outflow was .83. The apparent AVM inflow and outflow in small AVMs were significantly smaller than in medium AVMs (P < .001 for both groups). The apparent AVM inflow-to-outflow ratio was significantly larger in the hemorrhagic AVMs than in the nonhemorrhagic AVMs (P = .02). The apparent AVM inflow-to-outflow ratio was the only significant parameter that differed between nonhemorrhagic and hemorrhagic AVMs, suggesting that a poor drainage system may increase AVM pressure, potentially causing cerebral hemorrhage.

Correlation Of Functional Disorders In Cerebral Blood Flow With Cognitive Style Of Freshmen Students

In 97 healthy male freshmen students, we studied the parameters of arterial blood flow intensity (index of vascular resistance RI, amplitude-frequency index AFI), venous outflow (venous outflow index VOI), and tone and elasticity of cerebral vessels (diastolic index DIA, dicrotic index DIC, maximum blood velocity of fast filling in the artery Vmax, average blood velocity of slow filling in the artery Vav). Separately, we assessed the effectiveness of such mental operations as classification and analysis and studied the cognitive styles. In 35.9% of male freshmen, we revealed the functional dystonia of cerebral vessels with a pronounced inter-lacunar redistribution of blood flow to the region of internal carotid arteries. Their cognitive style had low rigidity, flexible control, strong cognitive automation, and low information processing speed. The cognitive style in freshmen without dystonic disorders was characterized by a balance of rigidity and flexibility of thinking, with a medium information processing speed.

Research on the Hierarchical Spatial Structure of the Urban Agglomeration of the Yellow River Ji-Shaped Bend

Despite the rising interest in understanding the various uses of space of flows, few studies have combined the traditional static urban development level with dynamic space of flows concepts. In the context of the coordinated development of the urban agglomeration of the Yellow River Ji-shaped bend (UAYB), this study identifies the hierarchical spatial structure of the UAYB through a combination of Baidu migration big data and traditional data. The following conclusions can be drawn. (1) The cities with the strongest regional comprehensive power are Ordos, Taiyuan, Hohhot, Yinchuan, and Yulin, which cause the UAYB to present a significant “center-periphery” spatial pattern. (2) The biggest population flows mostly occur between cities in the same province, while interprovincial population flows mainly exist between cities with the strongest comprehensive power. (3) The hierarchical spatial structure of the UAYB forms a multitree structure, with Ordos as the core. (4) The attractiveness of the UAYB is very weak, being only slightly attractive to individual surrounding provinces, while the population outflow index to economically developed areas is high. Several policy implications are proposed, which can provide important insights for planning intercity connections among the UAYB, in order to achieve more coordinated regional development.

Thermoplastic polyurethane with good mechanical and processing performances via blocking and deblocking of isocyanates

AbstractIncreasing the molecular weight of polyurethanes (PU) is an effective way to improve its mechanical properties, while, it is at the expense of sacrificing processability. Congruent modification in both mechanical and processing performances is still a challenge. Here, bis‐phenol‐A (BPA) derivatives, including tetrachlorobisphenol‐A and tetrabromobisphenol‐A, were chosen as the extender to synthesize thermoplastic PUs (TPU) containing blocked isocyanate units. This blocked isocyanate has a temperature‐responsive reversible reaction due to phenol urethane bonds, so as to ensure the good mechanical properties at the service temperature and better processing performance via deblocking into smaller molecular weight at the processing temperature; in addition, negative induction effect of the halogen substituents endow BPA derivatives with deblocking reaction at lower temperature. The experimental results confirmed that the blocking reaction carried out completely at 70°C, and accompanying by the dramatical increase of molecular weight. The obvious deblocking reaction happened at 140°C, where the average molecular weight of TPUs decreased from 22,600 g/mol to 13,690 g/mol. Meanwhile, the melt flow index increased significantly with the extension of heating time, indicating that the PU has good processing properties. After the deblocking and re‐blocking reactions were repeated alternatively, there is almost no change in its tensile properties, molecular weight and melt outflow index within two cycles under air atmosphere. This article proposes a strategy of congruent modification in both mechanical and processing performances of TPU.

Effects of an Exoskeleton-Assisted Gait Motor Imagery Training in Functional Brain Connectivity.

Lower-limb exoskeletons have been used in gait rehabilitation to facilitate the restoration of motor skills. These robotics systems could be complemented by Brain-Computer Interfaces (BCIs) to assist or rehabilitate people with walking disabilities. In this preliminary study, electroencephalography-based brain functional connectivity is analyzed during exoskeleton-assisted gait motor imagery (MI) training. Partial Directed Coherence (PDC) analysis was employed to assess the exchange of information flow between EEG signals during gait MI in four healthy subjects, two using an exoskeleton and two without using it. Besides, in order to explore the functional connectivity, an outflow index based on the number of significant directed connectivities revealed by the PDC analysis is proposed. We found that the outflow index increases in the central zone (C2, C3, C4) while decreases in the central-parietal (CP1, CP2) and fronto-central (FC1) zones when the training was assisted by an exoskeleton. The results obtained can be useful to obtain informative features for BCI applications as well as in motor rehabilitation.

Spectral energy distribution of the inner accretion flow around Sgr A* – clue for a weak outflow in the innermost region

Sgr A* represents a unique laboratory for the detailed study of accretion processes around a low-luminosity supermassive black hole (SMBH). Recent X-ray observations have allowed for spatially resolved modeling of the emission from the accretion flow around the SMBH, placing tight constraints on the flux and spectral shape of the accretion from the inner region with $r<10^3~r_g$, where $r_g$ is the gravitational radius of the black hole. We present here the first modeling of the multi-band spectral energy distribution (SED) of this inner region to better constrain the physical condition of the innermost accretion flow. Our modeling uses the Markov chain Monte Carlo (MCMC) method to fit the SED, accounting for the limitations on the accretion rate at the outer radius of $10^3~r_g$ from the earlier works and the domination of the accretion flow within $30~r_g$ to the sub-mm bump. It is found that the fitting results of the outflow index could be very different. If only the most luminous part of the SED, the sub-mm bump, is considered, the outflow index is about 0, while if low-frequency radio data and X-ray data are also included, the outflow index could be 0.37 or even higher. The great difference of the fitting results indicates that the outflow index should be variable along radius, with a strong outflow in the outer region and a weak outflow in the innermost region. Such weak outflow agrees with numerical simulations and is possible to explain the multi-band SED even better.

Quantification of severity of mitral regurgitation by simple Doppler echocardiographic “left ventricular early inflow–outflow index”

Quantification of severity of mitral regurgitation by simple Doppler echocardiographic “left ventricular early inflow–outflow index”

Diagnostic Value of Left Ventricular Early Inflow-Outflow Index in Determining Severity of Mitral Regurgitation

Background: Determining severity of mitral regurgitation (MR) is very important, asit is related with prognosis and management of the disease. Currently, there is no goldstandard exists for quantification of MR severity using echocardiography. AmericanSociety of Echocardiography (ASE) guidelines recommend several parameters basedon integrative criteria using color and spectral Doppler and anatomic measurement.Left Ventricular Early Inflow Outflow Index (LVEIO Index) was proposed as one parameterto assess the severity of MR by omitting geometric error from regurgitantvolume method. Thus, LVEIO index offers a simple, easy and accurate measurementin determining severity of MR.Methods: This study was a diagnostic test research with cross-sectional design. Thesubjects were all patients with organic mitral regurgitation who underwent echocardiographyexamination to measure severity of MR using the LVEIO index as well asother parameters measurements based on parameters of ASE guidelines. Diagnostictest was used to determine the sensitivity, specificity, positive predictive value, negativepredictive value and accuracy of LVEIO index.Results: Of 49 patients in this study, 23 of them have severe MR and 26 are non-severeMR patients. The proportion of gender between two groups almost similar with an agerange from 56 to 61 years and the most common etiology finding was degenerative MR.Echocardiography examination showed the ejection fraction in severe MR was 63±4.2%and 64±3.9% in non-severe MR. The value of LAVI, MPAP, E-wave, VC, EROA andLVEIO index increased parallel with severity of MR (LAVI; 67±18.2 vs. 40±14.2 ml/m2,MPAP; 28±12.8 vs. 20±12.6 mmHg, E-wave 1.5±0.3 vs. 1±0.2 m/s, VC 0.8±0.3 vs.0.5±0.1 cm, EROA 0.4±0.1 vs 0,2±0,1cm2, LVEIO 9±2,4 vs. 5±1,8). The sensitivity,specificity, and accuracy of LVEIO index for diagnosis of severe MR were 86%, 84%,and 89%, respectively.Conclusion: LVEIO can be proposed as a relatively simple, easy and accurate methodin determining severity of MR.

Evaluation of Geographic Indices Describing Health Care Utilization.

ObjectivesThe accurate measurement of geographic patterns of health care utilization is a prerequisite for the study of geographic variations in health care utilization. While several measures have been developed to measure how accurately geographic units reflect the health care utilization patterns of residents, they have been only applied to hospitalization and need further evaluation. This study aimed to evaluate geographic indices describing health care utilization.MethodsWe measured the utilization rate and four health care utilization indices (localization index, outflow index, inflow index, and net patient flow) for eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee replacement surgery, caesarean sections, hysterectomy, computed tomography scans, and magnetic resonance imaging scans) according to three levels of geographic units in Korea. Data were obtained from the National Health Insurance database in Korea. We evaluated the associations among the health care utilization indices and the utilization rates.ResultsIn higher-level geographic units, the localization index tended to be high, while the inflow index and outflow index were lower. The indices showed different patterns depending on the procedure. A strong negative correlation between the localization index and the outflow index was observed for all procedures. Net patient flow showed a moderate positive correlation with the localization index and the inflow index.ConclusionsHealth care utilization indices can be used as a proxy to describe the utilization pattern of a procedure in a geographic unit.

Zróżnicowanie przestrzenne i zmienność odpływu w zlewniach fliszowych na obszarze Masywu Babiej Góry

&lt;p&gt;The paper refers to spatial diversity and lability of outflow from Flysh type drainage basins. It also shows dynamics of mean and high discharge by defining the trend, the variability index and the periodicity of the hydrological parameters mentioned. The research has been taken in the partial drainage basins located in the upper drainage basin of Skawica (the streams of Czatożanka, Marków Potok, Rybny Potok, Jaworzyna) and in the upper drainage basin of Czarna Orawa (Kiczorka) at the Babia Góra slopes. The analyzed two-year period (2012–2013) has been characterized comparing to the multiannual period of 1973–2014. The hydrological and meteorological data have been obtained due to monitoring of the hydrological environment of Babiogórski National Park. The database includes the data gained from The Institute of Meteorology and Water Management research. Poland is the one of the less water-rich European countries. The unit outflow is only 5.5 dm3·s-1·km-2 (Fall 1997). The water outflow is very space and time varied through the whole country. The outflow from drainage basins of Babia Góra area is one of the biggest in Poland (about 30 dm3·s-1·km-2). The outflow index (rate of outflow?) from Babia Góra area is 88% per annum, which distinguishes this area from the Beskidy Mountains. During the winter semester the outflow index is 12.7% and during the summer semester it is 70% (Łajczak).&lt;/p&gt;&lt;p&gt;The outflow index and the seasonal lability of the outflow from the particular Babia Góra drainage basins are very varied which is the most noticeable between the northern and southern slopes located drainage basins, however the variety is also very clear to observe from the east to the west direction. The analyzed cycle were a general low-flow period including one thaw flood within this period (2012s) and several minor floods caused by severe rainfalls (2013s). The maximum unit outflow during the flood has been noticed in Czatożanka drainage basin and the minimum unit outflow has been noticed in Kiczorka drainage basin. The highest annual average unit outflow occurred within Marków Potok, and the lowest annual average unit outflow occurred within Czatożanka. The drainage basins located at the northern slopes of Babia Góra were characterized by big seasonal outflow fluctuation between winter and summer semesters. Only at the southern slopes in the Kiczorka drainage basin the outflow was not much varied comparing the particular semesters.&lt;/p&gt;

Left ventricular early inflow-outflow index: a novel echocardiographic indicator of mitral regurgitation severity.

BackgroundNo gold standard currently exists for quantification of mitral regurgitation (MR) severity. Classification by echocardiography is based on integrative criteria using color and spectral Doppler and anatomic measurements. We hypothesized that a simple Doppler left ventricular early inflow–outflow index (LVEIO), based on flow velocity into the left ventricle (LV) in diastole and ejected from the LV in systole, would add incrementally to current diagnostic criteria. LVEIO was calculated by dividing the mitral E-wave velocity by the LV outflow velocity time integral.Methods and ResultsTransthoracic echocardiography reports from Montefiore Medical Center and its referring clinics from July 1, 2011, to December 31, 2011 (n=11 235) were reviewed. The MR severity reported by a cardiologist certified by the National Board of Echocardiography was used as a reference standard. Studies reporting moderate or severe MR (n=550) were reanalyzed to measure effective regurgitant orifice area by the proximal isovelocity surface area method, vena contracta width, MR jet area, and left-sided chamber volumes. LVEIO was 9.3±3.9, 7.0±3.2, and 4.2±1.7 among those with severe, moderate, and insignificant MR, respectively (ANOVA P<0.001). By receiver operating characteristic analysis, area under the curve for LVEIO was 0.92 for severe MR. Those with LVEIO ≥8 were likely to have severe MR (likelihood ratio 26.5), whereas those with LVEIO ≤4 were unlikely to have severe MR (likelihood ratio 0.11). LVEIO performed better in those with normal LV ejection fraction (≥50%) compared with those with reduced LV ejection fraction (<50%) (area under the curve 0.92 versus 0.80, P<0.001). By multivariate logistic regression analysis, LVEIO was independently associated with severe MR when compared with vena contracta width, MR jet area, and effective regurgitant orifice area measured by the proximal isovelocity surface area method.ConclusionLVEIO is a simple-to-use echocardiographic parameter that accurately identifies severe MR, particularly in patients with normal LV ejection fraction.

A novel approach to flow estimation in tidal rivers

Reliable estimation of river discharge to the ocean from large tidal rivers is vital for water resources management and climate analyses. Due to the difficulties inherent in measuring tidal‐river discharge, flow records are often limited in length and/or quality and tidal records often predate discharge records. Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave as discharge increases. We use this phenomenon to develop a method of estimating river discharge for time periods with tidal data but no flow record. Employing sequential 32 day harmonic analyses of tidal properties, we calibrate San Francisco (SF), CA tide data to the Sacramento River delta outflow index from 1930 to 1990, and use the resulting relationship to hindcast river flow from 1858 to 1929. The M2 admittance (a ratio of the observed M2 tidal constituent to its astronomical forcing) best reproduces high flows, while low‐flow periods are better represented by amplitude ratios based on higher harmonics (e.g., ). Results show that the annual inflow to SF Bay is now 30% less than before 1900 and confirm that the flood of January 1862 was the largest since 1858.

Reversible increase of intraocular pressure in subclinical hypothyroid patients

The aim of the study was to analyse the relationship between the ocular parameters, namely intraocular pressure (IOP), and the early forms of subclinical hypothyroidism. Fifty-three subjects (9 male and 44 female) aged from 18 to 45 years (mean 32 +/- 7 years) were selected for this study. Twenty-nine met the criteria of subclinical hypothyroidism and 24 euthyroid subjects, age- and sex-matched, were used as controls. All individuals underwent a complete ocular examination, including visual field examination and serial measurement of IOP by means of a Goldmann tonometer. A tonographic examination was also performed. The hypothyroid patients showed a substantially higher pressure in both eyes compared with control subjects (right eye = 17.52 +/- 4.74 vs 13.42 +/- 1.95 mmHg, P < 0.0001; left eye = 17.55 +/- 3.99 vs 13.71 +/- 1.55 mmHg, P < 0.0001). Indeed, the tonometric pressure exceeded 18 mmHg in 11 out of the 29 (38%) patients in the right eye and in 8 out of 29 (27%) patients in the left eye. The outflow index was normal in all subjects except in two hypothyroid patients. After two months of L-thyroxine (L-T4) replacement therapy, only one patient continued to show tonometric values above 18 mmHg and the hypothyroid patients showed a significant reduction in mean IOP in both eyes compared with pre-treatment values (right eye = 14.96 +/- 1.32 mmHg, P < 0.0097; left eye = 15.03 +/- 1.38 mmHg, P < 0.0018). Treatment did not lead to any change in the outflow indices; however, the C value (outflow coefficient at the sclerocorneal corner) returned to normal in the two patients with increased pre-treatment tonographic values. These findings indicate that the intraocular pressure is increased even in subclinical hypothyroid patients and that, at this early stage, the impairment is fully reversible with L-T4 therapy.