Straight Neck Research Articles

Distribution of the Donetsk Type Beakers Among the Ingul Catacomb Culture Burials

The prominent pottery type of the Catacomb cultures of the northern Pontic steppe in 2500—2300 BC are the beakers of the Donetsk type. Donetsk beakers can be described as globular vessels with straight neck and articulated foot. Beaker’s body is often decorated with impressions of braid that form circles or a garland. Though the majority of Donetsk beakers originate from the burials of Donetsk Catacomb culture of the Seversky Donets basin, several beakers were found to the west from the Donetsk culture area. Currently, 14 Donetsk beakers coming from the Inhul Catacomb culture are known. Mapping of the Donetsk beakers found in the burials of the Inhul Catacomb culture indicates the distribution of the Eastern vessels among all local groups of the Inhul culture such as Molochansk, the North-Crimea, the Oril-Samara, the Southern and Northern Inhul and Kryvyi Rih territorial areas. As an exception can be named the Dniester-Southern Bug group. The latter is often described in historiography as an inclusion from outer influences during the second half of the 3rd millennia and the study of beakers is supported by such a conclusion. Mapping also reveals the concentration of Donetsk beakers near Kryvyi Rih copper ore basin, which had been exploited since the second half of the 4th millennia BC. It may be assumed that the appearance of Donetsk beakers represents the migration of Donetsk culture’s metallurgists who were searching for the new sources of raw materials. The distribution of the Donetsk Catacomb culture burials, as well as Donetsk beakers, allows reconstructing two routs of migration of the Donetsk people. Some of them could have come from the South, the North-Eastern Azov region. Others could have come from the North, the territory of the Left-bank Ukraine Forest-Steppe. Distribution areas of the Donetsk and Inhul cultures collide on the line Poltava-Lozova which is attested by the materials of Storozhove, Ternivka and Petrivka burial mound. Thus, numerous examples of Donetsk beakers found inside the burials of the Inhul Catacomb culture indicate a long-running migration of the Donetsk people from the Sevesky Donets basin to the Ukrainian Right-bank steppe during the period from 2500 to 2300 BC.

Hip hemiarthroplasty with modular neck: is it useful in residents' learning curve? A prospective clinical trial.

The number of femoral neck fractures (FNFs) worldwide will drastically increase in the next few decades, reaching 6.3 million by 2050. In the future, therefore, newly-qualified orthopaedic surgeons will treat this kind of injury more frequently than in past decades. This prospective observational study aims to assess whether hip hemiarthroplasty with modular neck, performed via the Hardinge approach, can be safely carried out by orthopaedic residents. Patients referred to our Level I trauma centre, between January 2016 and June 2017, with displaced intra-articular femoral fractures, were prospectively recruited. All patients underwent cemented modular bipolar hip hemiarthroplasty (Profemur Z, MicroPort Orthopedics Inc., Arlington, TN, USA) via the Hardinge approach, with the patient positioned in lateral decubitus. The surgical procedures were performed by the same surgical and anesthesiology team, under spinal anaesthesia. All patients underwent clinical and radiographic follow-up up to 24 months. Complications and re-operations were recorded. Clinical evaluation was performed using the Harris Hip Score (HHS), Osteoporosis Quality of Life Questionnaire QUALEFFO-41 and EuroQol-5D (EQ-5D) questionnaire. Anteroposterior pelvis x-rays were performed preoperatively, postoperatively and at 1, 3, 6, 12 and 24 months follow-up. 118 patients met the inclusion criteria (male: 50; female: 68; mean age: 74.3 years; range 65-88 years) and were included in the current study. 67 patients out of 118 (56.8%) were managed by senior orthopaedic surgeons (Group A), whereas the remaining 51 patients out of 118 (43.2%) were treated by orthopaedic residents (Group B). Hip hemiarthroplasties performed by senior surgeons showed the prevalent use of straight (short or long) necks, whereas, in surgical procedures performed by residents, there was a significantly higher use of varus/valgus, anteverted or retroverted necks. The overall complication rate was significantly higher in Group-B patients, compared with Group-A patients (p = 0.002). The length of hospital stay and the mean clinical scores at 24 months follow-up showed no significant differences. Hip hemiarthroplasty with modular neck can be safely employed during the learning curve of orthopaedic residents. Great efforts, however, should be made in future to improve residents' training in the management of FNFs.

Crop Modeling Application to Improve Irrigation Efficiency in Year-Round Vegetable Production in the Texas Winter Garden Region

Given a rising demand for quality assurance, rather than solely yield, supplemental irrigation plays an important role to ensure the viability and profitability of vegetable crops from unpredictable changes in weather. However, under drought conditions, agricultural irrigation is often given low priority for water allocation. This reduced water availability for agriculture calls for techniques with greater irrigation efficiency, that do not compromise crop quality and yield, and that provide economic benefit for producers. This study developed vegetable growing models for eight different vegetable crops (bush bean, green bean, cabbage, peppermint, spearmint, yellow straight neck squash, zucchini, and bell pepper) based on data from several years of field research. The ALMANAC model accurately simulated yields and water use efficiency (WUE) of all eight vegetables. The developed vegetable models were used to evaluate the effects of various irrigation regimes on vegetable growth and production in several locations in the Winter Garden Region of Texas, under variable weather conditions. Based on our simulation results from 960 scenarios, optimal irrigation amounts that produce high yield as well as reasonable economic profit to producers were determined for each vegetable crop. Overall, yields for all vegetables increased as irrigation amounts increased. However, irrigation amounts did not have a sustainable impact on vegetable yield at high irrigation treatments, and the WUEs of most vegetables were not significantly different among various irrigation regimes. When vegetable yields were compared with water cost, the rate decreased as irrigation amounts increased. Thus, producers will not receive economic benefits when vegetable irrigation water demand is too high.

Appropriate Neck Flexion Without Head-hitting Decreases The Thrown Player’S Risk Of Brain Injury In Judo

PURPOSE: Judo is one of the worldwide sports and its competitive athletic events have been held in Olympic Games. Serious brain injuries, however, have been occasionally noted in judo practices and/or competitions. Since the patterns and severities of brain injuries largely depend on the kinematics of the thrown players, it is essential to investigate the mechanism of brain injury from the biomechanical viewpoint in popular throwing techniques. The aim of this study is to evaluate the brain injury criterion (BrIC), an indicator of brain injury, with measuring the presence or absence of head-hitting on the anthropomorphic test device (ATD) in judo throwing technique Ouchi-gari. METHODS: A male judo expert (thrower) threw an ATD for 6 times by Ouchi-gari with or without head-hitting, respectively. The ATD with a straight neck component necessarily hit the occipital region on the mat, whereas an angled component was designed for preventing the ATD’s head-hitting. A 3-axis angular rate sensor, mounted in the gravity center of the ATD’s head, assessed head axial angular velocity in each trial. To evaluate the ATD’s head impact quantitatively, we calculated the BrIC from the head axial angular velocity. High-speed digital video cameras also recorded the kinematics of the ATD’s whole body during trials. RESULTS: In all trials, the largest angular velocities were recorded in the phase of the initial head (with head-hitting) or back (without head-hitting) contacting to the mat. The peak BrIC values of ATD ranged from 0.94 to 2.27 (with head-hitting) and 0.54 to 0.91 (without head-hitting). The average BrIC value with head-hitting (1.62 ± 0.22, mean ± S.E.) trials was significantly higher than those without head-hitting (0.73 ± 0.08) trials (p<0.05). Four out of six trials with head-hitting scored BrIC values larger than 1.0, which implies the human tolerance limit for serious brain injury. However, BrIC values were less than 1.0 in all other trials without head-hitting. CONCLUSIONS: These results suggested that thrown player’s break-fall technique, with appropriate neck flexion to avoid head-hitting, decreases the BrIC value effectively and the risk of serious brain injuries in judo.

A Helmholtz Resonator with Spiral Neck for Analyte Concentration Measurement in Low Frequency Range

Helmholtz resonators (HR) have been proven to have feasibility for sensor applications with good performance. However, for biosensor application, when the amount of test sample is limited, the operating frequency tends to be very high, which may bring challenges of resonance excitation and frequency measurement. In this paper, a modified HR was proposed for biosensor application at a lower frequency, by designing the neck of the HR as a type of an Archimedes spiral, which can increase the neck length as much as possible without occupying much space. The resonant frequency of the proposed HR was derived by treating it as an HR with a straight neck with the equivalent length. An analytical example was calculated and verified by acoustic finite element analysis, and the results clearly showed that the frequency decreases in comparison to that of the conventional HR. Based on the underlying theory, the measurement principle was proposed and the experiment setup was established using a 3D-printed structure. The experiment was done using test solutions with different glucose concentrations, whose results showed consistency with the analytical results and noticeable frequency increases with the glucose concentration. Prospective results of the proposed HR after miniaturization show an operating frequency around 3 kHz when the amount of test sample is 0.1 mL, which will facilitate use of the common acoustic power source and acoustic pressure sensors in the sensing system.

Excited resonance widths for Helmholtz resonators with straight neck

We consider resonances associated with excited eigenvalues of the cavity of a general Helmholtz resonator with straight neck. Under the assumption that the neck stays away from the nodal set of the corresponding eigenstate, we generalise the optimal exponential lower bound on the width of the resonance, that we have obtained in a previous paper for the ground resonance only.

Effect of a modular neck hip prosthesis on anteversion and hip rotation in total hip arthroplasty for developmental dysplasia of the hip.

Total hip arthroplasty (THA) is often required to decrease the excessive anatomical femoral anteversion (AA) in developmental dysplasia of the hip. Studies have recommended decreasing the AA via the use of a retroverted modular neck. However, hip rotation after THA may strengthen or weaken the effect of changing the AA. Thus, the present study analyzed the effect of a retroverted neck on AA and hip rotation. Patients who underwent THA using a straight neck (ST group) or a 15° retroverted neck (RV group) in a version changeable dual modular system (Mainstay stem, Kyocera, Kyoto, Japan) were retrospectively reviewed. After matching for age, body mass index, and surgical approach, 44 patients were included in each group. The AA and hip rotation (femoral rotational angle: FRA) were measured on CT images acquired preoperatively and 1month after THA, and were compared between the groups. The mean ± standard deviation preoperative AA of the ST group (26.1 ± 10.7°) was significantly smaller than that of the RV group (44.2 ± 7.8°) (p < 0.001). In contrast, the postoperative AA did not significantly differ between the groups (ST group 27.5 ± 9.8°, RV group 25.1 ± 8.3°, p = 0.406). The change in FRA after THA did not significantly differ between the groups (ST group - 3.8 ± 9.9°, RV group - 3.5 ± 9.1°, p = 0.841). In conclusion, a 15° retroverted neck was useful in controlling AA in hips with excessive AA, and the change in FRA after THA did not differ between the ST group and the RV group.

Modeling acoustic resonators using higher-order equivalent circuits

Helmholtz resonators are widely used, but classical models for the resonators, such as the lumped-element equivalent circuit, are inaccurate for most geometries. This article presents higher-order equivalent circuits for describing the resonators based on the one-dimensional wave equation. Impedance expressions are also derived. These circuits and expressions are given for various constituent resonator components, which may be combined to model resonators with curved, tapered, and straight necks. Resonance frequency predictions using this theory are demonstrated on two realistic resonators. The higher-order predictions are also applied to the theory of side branch attenuators in a duct and the theory of resonator coupling with a mode of an enclosure.

The ideal position of the peritoneal dialysis catheter is not always ideal.

Peritoneal catheter dysfunction is a frequent complication of peritoneal dialysis (PD). Traditionally, dysfunction has been attributed to catheter malposition, but whether the location of the catheter tip in the small pelvis really determines proper function is unclear. We reviewed 900 abdominal X-ray images of PD patients from a 7-year period in two PD units that use different catheter types (straight and Swan Neck Curled). In 52% of the images, the dialysis catheter tip was located in the ideal position in the small pelvis and in 48% in other sites. Peritoneal catheter function was normal at the time of imaging in 87% of those with ideal catheter tip position, and in 74% of those with other than ideal position. The tip was located in small pelvis in 35% of images performed during catheter dysfunction and in 56% of those performed during normal catheter function. There were no differences between two catheter types. The positive predictive value of abdominal X-ray images to predict catheter function was 26%, and the negative predictive value 87%. We also found a significant positive correlation between polycystic kidney disease and normal catheter function. In contrast, obese patients were more likely to have catheter malfunction. Previous abdominal surgery was not associated with catheter dysfunction. Our data showed a higher probability of normal function of peritoneal catheters whose tips were located in the small pelvis. However, also malpositioned catheters generally functioned well, and malpositioning of the PD catheter did not in itself explain its malfunction.

Pottery from the Defensive Moat of “Citadel” Site of Dykyi Sad Hillfort

The article deals with pottery from the filling of the defensive moat of “Citadel” site of the hillfort Dykyi Sad. The moat has a shape of a large arc that is elongated along the line South-East–North-West. The length of the investigated part is 1.30 m, width – 5.0 m, depth – 3.0-3.10 m. There were identified more than twenty-two thousand fragments of pottery, belonging to about 2500 vessels of various purposes. The moat filling can be divided into three levels: – upper level (thickness 1.0 m), in which the expressionless ceramics were fixed (about 1000). – middle level (thickness 1.0 m), in which the saturation of ceramic fragments increases (approximately 10000). – lower level (thickness 1.0 m), in which the number of fragments of ceramic ware is practically similar to the middle level (about 11000). There were selected 165 complete and partly preserved vessels from the middle (81 fragment) and lower filling levels (84 fragments), suitable for formal classification. The subject of the study is moulded ware from the middle and lower levels of moat filling. All material is divided into two groups: closed (120 fragments) and open shapes (41 fragment). Each group is divided into types. Pottery of closed group consists of pots, jars, cups, ladle, large pots. The open group wares are bowls, cups, braziers, riddles. Among the forms there were specified types due to the shape of neck and rim. According to the type there have been classified variations within body shapes. A separate, special, group is composed with non-stan¬dard (miniature) dishes, which can be considered as for cult purposes (4 fragments). It was found that among closed group dominated squat cups (32,5 %) and pots with arc-like neck (14,2 %); the lowest number is represented by elongated cups (4,2 %) and pots with conical neck (1.6 %). Among the dishes of open group there are bowls (36.6 %), and cups (31,7 %); the least represented are flat braziers with segmental-cut body form (7,3 %), bowls with elongated straight neck (7.3 %), riddles (7.3 %) and flat braziers with a small rim (4.9 %). Among the miniature (cult) dishes there are two jars (50 %), a cup (25 %) and a small pot (25 %). Pottery from the moat filling relates to the ceramics fixated in the “Citadel” premises of the hillfort Dykyi Sad and is found among mat¬erials of well-known settlements and burial grounds of Bilozerka culture period of the North-Western Pontic region. In the cultural and chronological aspect the ceramics of lower level moat filling of the “Citadel”, there are mostly fragments refering to the early stage of Bilozerka culture and early stage of the settlement occurence (end of 13th – beginning of 12th c. BC), and the ceramics of middle level relates to the main period of the hillfort existence (12th – 11th c. BC).

Effect of neck design on peri-implant tissue responses in external connection type implant : a prospective pilot clinical study

This clinical study was conducted to evaluate the clinical effects of a concave neck of external connection type implant fixture designed for platform switching on the peri-implant tissue responses. Two types of implants with different neck designs were implanted in 20 patients. For the experimental group, the bioseal(BS) implant fixtures with 's' shaped concave profile on the neck were used, and non-bioseal(NBS) implant fixtures with a straight profile on the neck were used as control(Total of 40 implants, NBS: n = 19, BS: n=21). During the one-year period after implant placement, implant survival rate, marginal bone resorption, bleeding, plaque, and complications were evaluated. The survival rate of NBS and BS group was 94.74% and 90.48%, respectively. There was no significant difference on marginal bone resorption, bleeding and plaque between the two groups (P&gt;.05). Within the limits of the present study, implants with a concave neck design showed similar clinical results to implants with a straight neck design on the peri-implant tissue responses. Longitudinal clinical studies are necessary to confirm more effective clinical results.

Russula ahmadii (Basidiomycota, Russulales), a new species in section Ingratae and its ectomycorrhiza from coniferous forests of Pakistan

Russula ahmadii, a new species and its ectomycorrhiza are described and illustrated from coniferous forests of Pakistan, based on morphological characteristics and molecular phylogenetic data. The species is characterized by small to medium size basidiomata, a dark brown to greyish brown, tuberculate striate, and depressed pileus with dark brown spots in the centre, a chambered stipe having brownish patches towards the base, globose to subglobose amyloid basidiospores, having covered with bifurcated verrucose ornamentation connected by partial reticulum. Its ectomycorrhiza is typical of the genus Russula and is characterized by the presence of abundant lageniform cystidia with a straight neck and branched emanating hyphae with frequent clamp connections. Phylogenetic analyses based on ITS and LSU sequences support erection of the new species. Phylogenetic network analysis revealed its close position to R. pectinatoides. ITS sequences from ectomycorrhiza of Cedrus deodara also clustered with sequences from basidiomata of R. ahmadii confirming its mycorrhizal status. Phylogenetic analyses and morphological features placed the new species in R. section Ingratae.

Neck Muscle Moment Arms Obtained In-Vivo from MRI: Effect of Curved and Straight Modeled Paths.

Musculoskeletal models of the cervical spine commonly represent neck muscles with straight paths. However, straight lines do not best represent the natural curvature of muscle paths in the neck, because the paths are constrained by bone and soft tissue. The purpose of this study was to estimate moment arms of curved and straight neck muscle paths using different moment arm calculation methods: tendon excursion, geometric, and effective torque. Curved and straight muscle paths were defined for two subject-specific cervical spine models derived from in vivo magnetic resonance images (MRI). Modeling neck muscle paths with curvature provides significantly different moment arm estimates than straight paths for 10 of 15 neck muscles (p<0.05, repeated measures two-way ANOVA). Moment arm estimates were also found to be significantly different among moment arm calculation methods for 11 of 15 neck muscles (p<0.05, repeated measures two-way ANOVA). In particular, using straight lines to model muscle paths can lead to overestimating neck extension moment. However, moment arm methods for curved paths should be investigated further, as different methods of calculating moment arm can provide different estimates.

Resonance widths for general Helmholtz resonators with straight neck

We prove an optimal exponential lower bound on the width of the resonance associated to the first eigenvalue of the cavity for a general Helmholtz resonator with straight neck, in any dimension.

An extended neck versus a spiral neck of the Helmholtz resonator

This paper focuses on improving the noise attenuation performance of the Helmholtz resonator (HR) at low frequencies with a limited space. An extended neck or a spiral neck takes the place of the traditional straight neck of the HR. The acoustic performance of the HR with these two types of necks is analyzed theoretically and numerically. The length correction factor is introduced through a modified one-dimensional approach to account for the non-planar effects that result from the neck being extended into the cavity. The spiral neck is transformed to an equivalent straight neck, and the acoustic performance is then derived by a one-dimensional approach. The theoretical prediction results fit well with the Finite Element Method (FEM) simulation results. Without changing the cavity volume of the HR, the resonance frequency shows a significant drop when the extended neck length or the spiral neck length is increased. The acoustic characteristics of HRs with these two different neck types have a potential application in noise control, especially at low frequencies within a constrained space.

The effects of stabilization exercises using a sling and stretching on the range of motion and cervical alignment of straight neck patients.

[Purpose] The purpose of this study was to assess how stretching exercise training and sling exercise training for stabilization influences the cervical spine angles and cervical range of motion of straight neck patients. [Subjects and Methods] Twenty straight neck patients were selected as subjects and they were randomly divided into two groups, the stretching and sling stabilization exercise groups which 60 minutes of exercise three times a week for 6weeks. All the subjects in each of the two respective study groups received an X-ray and had their cervical range of motion measured, both before and after the exercise. [Results] When differences in the cervical spine angle between the pre- and the post-test were checked, it was found that only the stretching exercise group showed statistically significant decreases in the craniovertebral angle and the cranial rotation angle. When differences in the range of motion between pre- and post-test were checked, the sling stabilization exercise group showed a significant change in flexion, right rotation, left lateral bending, right lateral bending, and the stretching exercise group showed a significant change in left rotation, left lateral bending, and right lateral bending. [Conclusion] These results indicate that both types of exercises are effective at improving the cervical range of motion of straight neck patients, and that the stretching exercise was more effective than the sling stabilization exercise at improving cervical spine angles.

What if you stretch the IFU? A mechanical insight into stent graft Instructions For Use in angulated proximal aneurysm necks

Endovascular treatment for patients with a proximal neck anatomy outside instructions for use is an ongoing topic of debate in endovascular aneurysm repair. This paper employs the finite element method to offer insight into possible adverse effects of deploying a stent graft into an angulated geometry. The effect of angulation, straight neck length and device oversize was investigated in a full factorial parametric analysis. Stent apposition, area reduction of the graft, asymmetry of contact forces and the ability to find a good seal were investigated. Most adverse effects are expected for combinations of high angulation and short straight landing zones. Higher oversize has a beneficiary effect, but not enough to compensate the adverse effects of (very) short and angulated angles. Our analysis shows that for an angle between the suprarenal aorta and proximal neck above 60°, proximal kinking of the device can occur. The method used offers a engineering view on the morphological limits of EVAR for a clinically used device.

Influences of implant neck design and implant–abutment joint type on peri-implant bone stress and abutment micromovement: Three-dimensional finite element analysis

ObjectivesOcclusal overloading is one of the causes of peri-implant bone resorption, and many studies on stress distribution in the peri-implant bone by three-dimensional finite element analysis (3D FEA) have been performed. However, the FEA models previously reported were simplified and far from representing what occurs in clinical situations. In this study, 3D FEA was conducted with simulation of the complex structure of dental implants, and the influences of neck design and connections with an abutment on peri-implant bone stress and abutment micromovement were investigated. MethodsThree types of two-piece implant CAD models were designed: external joint with a conical tapered neck (EJ), internal joint with a straight neck (IJ), and conical joint with a reverse conical neck (CJ). 3D FEA was performed with the setting of a “contact” condition at the component interface, and stress distribution in the peri-implant bone and abutment micromovement were analyzed. ResultsThe shear stress was concentrated on the mesiodistal side of the cortical bone for EJ. EJ had the largest amount of abutment micromovement. While the von Mises and shear stresses around the implant neck were concentrated on the labial bone for IJ, they were distributed on the mesiodistal side of the cortical bone for CJ. CJ had the least amount of abutment micromovement. SignificanceImplants with a conical joint with an abutment and reverse conical neck design may effectively control occlusal overloading on the labial bone and abutment micromovement.

Clinical and Radiological Outcomes of Two Implants with Different Prosthetic Interfaces and Neck Configurations: Randomized, Controlled, Split‐Mouth Clinical Trial

Peri-implant bone loss seems to occur following implant placement/loading regardless of all the efforts to eliminate it. Several factors, including surgical trauma, biologic width establishment, lack of passive fit of the superstructures, implant-abutment microgap, and occlusal overloading, may increase peri-implant bone loss. Over the years, new interface designs were introduced and clinical studies suggest that internal conical connection and platform shifting may be advantageous for marginal bone preservation. To compare clinical and radiological outcomes of two implant designs with different prosthetic interfaces and neck configurations in a randomized, controlled, split-mouth clinical trial. Thirty-four partially edentate patients randomly received at least one internal conical connection with back-tapered collar and platform shifting design or external-hexagon implants with flat-to-flat implant-abutment interface. Primary end point was peri-implant bone level changes at different time points, failures of implants and/or prosthesis, any complications, implant stability quotient (ISQ) values, and periodontal parameters. No dropout occurred. Marginal bone changes were statistically significantly different with better results for the internal conical connection. No implants and prosthesis failures have been observed, yielding a cumulative survival rate of 100%. A high ISQ value was found for both implants, and no statistically significant difference was found for ISQ mean values between interventions at each time point (p > .05). All implants showed no bleeding on probing and a very slight amount of plaque at the 1-year-in-function visit. Both implant designs investigated performed similarly in terms of failure rates, providing successful results up to 1 year after loading. The back-tapered neck configuration with conical connection and built-in platform shifting showed statistically lower marginal bone loss than straight neck configuration with flat-to-flat implant-abutment interface and external-hexagonal connection.

Outbreak of Cucurbit Powdery Mildew on Watermelon Fruit Caused by Podosphaera xanthii in Southwest Florida.

Cucurbit powdery mildew caused by the obligate parasite Podosphaera xanthii occurs commonly on foliage, petioles, and stems of most cucurbit crops grown in the United States. (3). However, in the field, fruit infection on cucurbits including watermelon (Citrullus lanatus), is rarely, if ever, observed (2). Consequently, it was atypical when severe powdery mildew-like symptoms were observed on seedless and seeded watermelon fruit on several commercial farms in southwestern Florida during November and December 2010. Severe powdery mildew was also observed on 'Tri-X 313' and 'Mickey Lee' fruit grown at SWFREC, Immokalee, FL. Infected fruit developed poorly and were not marketable. Powdery mildew symptoms were mainly observed on young immature fruit, but not on mature older fruit. Abundant powdery mildew conidia occurred on fruit surface, but not on the leaves. Conidia were produced in chains and averaged 35 × 21 μm. Observation of conidia in 3% KOH indicated the presence of fibrosin bodies commonly found in the cucurbit powdery mildew genus Podosphaera (3). Orange-to-dark brown chasmothecia (formerly cleisthothecia) containing a single ascus were detected on the surface of some fruit samples. Conidial DNA was subjected to PCR using specific primers designed to amplify the internal transcribed spacer (ITS) region of Podosphaera (4). The resulting amplicons were sequenced and found to be 100% identical to the ITS sequences of P. xanthii in the NCBI database (D84387, EU367960, AY450961, AB040322, AB040315). Sequences from the watermelon fruit isolate were also identical to several P. fusca (synonym P. xanthii), P. phaseoli (GQ927253), and P. balsaminae (AB462803) sequences. On the basis of morphological characteristics and ITS sequence analysis, the pathogen infecting watermelon fruit can be considered as P. xanthii (1,3,4). The powdery mildew isolate from watermelon fruit was maintained on cotyledons of squash (Cucurbita pepo, 'Early Prolific Straight Neck'). Cotyledons and leaves of five plants each of various cucurbits and beans were inoculated with 10 μl of a conidial suspension (105conidia/ml) in water (0.02% Tween 20). Two weeks after inoculation, abundant conidia were observed on cucumber (Cucumis sativus, 'SMR-58') and melon (Cucumis melo) powdery mildew race differentials 'Iran H' and 'Vedrantais'. However, no growth was observed on melon differentials 'PI 414723', 'Edisto 47', 'PMR 5', 'PMR 45', 'MR 1', and 'WMR 29' (2,3). The powdery mildew isolate from watermelon fruit behaved as melon race 1 (3). Mycelium and conidia were also observed on fruit surface of watermelon 'Sugar Baby' and a susceptible U.S. plant introduction (PI 538888) 3 weeks after inoculation. However, the disease was not as severe as what was observed in the fields in fall 2010. The pathogen did not grow on plants of Impatiens balsamina or on select bean (Phaseolus vulgaris) cultivars ('Red Kidney', 'Kentucky Blue', and 'Derby Bush'), but did grow and produce abundant conidia on 'Pinto bush bean'. Powdery mildew on watermelon fruit in production fields can be considered as a potentially new and serious threat requiring further studies to develop management strategies.