Tracking control design for fractional order systems: A passivity-based port-Hamiltonian framework

This article focuses on the design of tracking control for chaotic fractional order systems subjected to perturbations in a port-Hamiltonian framework. The fractional order systems of general form are modeled into port-controlled Hamiltonian form. Then, the extended results on the dissipativity, energy balance, and passivity of the fractional order systems are proved and presented in this paper. The port-controlled Hamiltonian form of the fractional order systems are proved to be asymptotically stable via energy balancing concept. Furthermore, a tracking controller is designed for the fractional order port-controlled Hamiltonian form by utilizing the matching conditions of the port-Hamiltonian systems. Stability of the system is established and analyzed explicitly for the closed-loop system with the help of direct Lyapunov method. Finally, an application example is solved with simulation results and discussions to prove the effectiveness of the propounded control design approach.

Prevalence and barriers of reporting needle-stick injures amongst government pharmacists working in Perak, Malaysia

INTRODUCTION

Needle-stick injuries (NSIs) are common amongst healthcare workers including pharmacists. Studies have reported a range of 0-5.65 per 1,000 pharmacists handling vaccinations that suffered at least one incident of NSI. The objective of this study was to determine the prevalence of NSI and the barriers encountered in reporting it amongst government pharmacists working in Perak.

MATERIALS AND METHODS

This was a cross-sectional study conducted amongst all government pharmacists in Perak. We excluded those who did not consent or were unreachable electronically. The researchers provided an online link that was forwarded to all heads of departments in Perak via social media. The respondents answered their demographic details, questions assessing their knowledge of NSI transmissible diseases, needle-stick handling practices, detail experiences of them suffering an NSI (all self-developed questionnaires), and their barriers in reporting an NSI (validated questionnaire). All responses were auto-tabulated in an excel sheet. A sample size of 516 pharmacists was needed for this study. A respondent was deemed to have inadequate knowledge when they answered any question wrongly about NSI knowledge-related questions and inappropriate practice in needle handling when respondents answered any questions wrongly for questions assessing practices.

RESULTS

A total of 524 pharmacists participated. The overall prevalence of NSI was 23.1% (n=121), of which, those with contaminated NSI were 10.3% (n=54, 95%CI: 7.9-13.30). Twothirds of the participants (66.6%) had inadequate knowledge and nearly all of them were unable to describe the appropriate needle-handling practices (94.7%). Amongst the reported barriers were "not knowing whose duty it was to report an NSI" (45.5%) and "busy schedules" (44.7%).

CONCLUSION

One in every five pharmacists in the state of Perak had a history of NSI, and 1 in every 10 had sustained a contaminated NSI. The barriers to reporting a NSI were mainly due to uncertainty about whose responsibility to report the incident and being too busy to report it.

Field-resolved high-order sub-cycle nonlinearities in a terahertz semiconductor laser

The exploitation of ultrafast electron dynamics in quantum cascade lasers (QCLs) holds enormous potential for intense, compact mode-locked terahertz (THz) sources, squeezed THz light, frequency mixers, and comb-based metrology systems. Yet the important sub-cycle dynamics have been notoriously difficult to access in operational THz QCLs. Here, we employ high-field THz pulses to perform the first ultrafast two-dimensional spectroscopy of a free-running THz QCL. Strong incoherent and coherent nonlinearities up to eight-wave mixing are detected below and above the laser threshold. These data not only reveal extremely short gain recovery times of 2 ps at the laser threshold, they also reflect the nonlinear polarization dynamics of the QCL laser transition for the first time, where we quantify the corresponding dephasing times between 0.9 and 1.5 ps with increasing bias currents. A density-matrix approach reproducing the emergence of all nonlinearities and their ultrafast evolution, simultaneously, allows us to map the coherently induced trajectory of the Bloch vector. The observed high-order multi-wave mixing nonlinearities benefit from resonant enhancement in the absence of absorption losses and bear potential for a number of future applications, ranging from efficient intracavity frequency conversion, mode proliferation to passive mode locking.

High-speed THz spectroscopic imaging at ten kilohertz pixel rate with amplitude and phase contrast

By combining the advantages of the high-speed ASOPS technology and efficient THz generation, we have realized a high-speed laser-based spectroscopic THz imaging system with more than 10,000 pixels per second acquisition speed and an excellent signal-to-noise ratio of more than 100. Unlike THz line cameras or mm-wave intensity detectors, the present device allows for a much higher spatial resolution and attributes each imaging pixel with phase and amplitude information up to several THz while simultaneously maintaining a very high scanning speed unmatched by any other technique presented so far. The high-speed acquisition allows for samples to be scanned even at sample velocities of 5 m/s or higher while preserving the fundamental resolution limit of the THz radiation, which is on the order of 500 µm in the present case.

Engineered far-fields of metal-metal terahertz quantum cascade lasers with integrated planar horn structures

The far-field emission profile of terahertz quantum cascade lasers (QCLs) in metal-metal waveguides is controlled in directionality and form through planar horn-type shape structures, whilst conserving a broad spectral response. The structures produce a gradual change in the high modal confinement of the waveguides and permit an improved far-field emission profile and resulting in a four-fold increase in the emitted output power. The two-dimensional far-field patterns are measured at 77 K and are agreement in with 3D modal simulations. The influence of parasitic high-order transverse modes is shown to be controlled by engineering the horn structure (ridge and horn widths), allowing only the fundamental mode to be coupled out.

Optical sideband generation up to room temperature with mid-infrared quantum cascade lasers

Mid-infrared (MIR) sideband generation on a near infrared (NIR) optical carrier is demonstrated within a quantum cascade laser (QCL). By employing an externally injected NIR beam, E(NIR), that is resonant with the interband transitions of the quantum wells in the QCL, the nonlinear susceptibility is enhanced, leading to both frequency mixing and sideband generation. A GaAs-based MIR QCL (E(QCL) = 135 meV) with an aluminum-reinforced waveguide was utilized to overlap the NIR and MIR modes with the optical nonlinearity of the active region. The resulting difference sideband (E(NIR) - E(QCL)) shows a resonant behavior as a function of NIR pump wavelength and a maximum second order nonlinear susceptibility, χ((2)), of ~1 nm/V was obtained. Further, the sideband intensity showed little dependence with the operating temperature of the QCL, allowing sideband generation to be realized at room temperature.

20 THz broadband generation using semi-insulating GaAs interdigitated photoconductive antennas

We demonstrate broadband (20 THz), high electric field, terahertz generation using large area interdigitated antennas fabricated on semi-insulating GaAs. The bandwidth is characterized as a function of incident pulse duration (15-35 fs) and pump energy (2-30 nJ). Broadband spectroscopy of PTFE is shown. Numerical Drude-Lorentz simulations of the generated THz pulses are performed as a function of the excitation pulse duration, showing good agreement with the experimental data.

Mode-locking of a terahertz laser by direct phase synchronization

A novel scheme to achieve mode-locking of a multimode laser is demonstrated. Traditional methods to produce ultrashort laser pulses are based on modulating the cavity gain or losses at the cavity roundtrip frequency, favoring the pulsed emission. Here, we rather directly act on the phases of the modes, resulting in constructive interference for the appropriated phase relationship. This was performed on a terahertz quantum cascade laser by multimode injection seeding with an external terahertz pulse, resulting in phase mode-locked terahertz laser pulses of 9 ps duration, characterized unambiguously in the time domain.

Detection of a possible case of pulmonary tumour thromboembolism by endobronchial ultrasound

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Integrated injection seeded terahertz source and amplifier for time-domain spectroscopy

We used a terahertz (THz) quantum cascade laser (QCL) as an integrated injection seeded source and amplifier for THz time-domain spectroscopy. A THz input pulse is generated inside a QCL by illuminating the laser facet with a near-IR pulse from a femtosecond laser and amplified using gain switching. The THz output from the QCL is found to saturate upon increasing the amplitude of the THz input power, which indicates that the QCL is operating in an injection seeded regime.

The "silver-nitrate-oma"

This case report demonstrates and emphasises the unusual radiographic appearance of silver nitrate treatment in a 30-year-old patient, who subsequently underwent excision biopsy of a presumed potentially malignant lesion.

Estrogen inhibits NPY secretion through membrane-associated estrogen receptor (ER)-α in clonal, immortalized hypothalamic neurons

OBJECTIVE

Estrogen (E(2)) has an inhibitory effect on food intake by acting centrally in the hypothalamus, although it is not clear which hypothalamic neurons are involved in this process. Earlier studies from our lab and others have implicated neuropeptide Y (NPY) as an important central anorexigenic target of E(2). This study was designed to investigate whether E(2) can directly regulate NPY secretion and examine the cellular mechanisms and receptors responsible for this anorexigenic action of E(2).

DESIGN

Clonal, murine, hypothalamic neuronal cell models, mHypoE-42 and mHypoA-2/12, were investigated for NPY secretory responses to 17β-estradiol (E(2)) in the presence or absence of pharmacological inhibitors directed against the phosphatidylinositol-3-kinase (PI3K), mitogen-activated protein kinase (MAPK) and AMP-activated kinase (AMPK) pathways or to estrogen receptor (ER) specific agonists/antagonists.

MEASUREMENTS

The presence of hypothalamic markers and characterization of neuronal cell lines was completed with polymerase chain reaction. NPY levels were measured using an enzyme immunoassay (EIA). The expression of ER-α and caveolin-1 was analyzed using immunocytochemistry.

RESULTS

E(2) significantly decreased NPY secretion in both the mHypoE-42 and mHypoA-2/12 neurons. The E(2)-mediated repression of NPY secretion in the mHypoE-42 and mHypoA-2/12 neurons required ER-α, but not ER-β, as shown by studies using an ER-specific agonist/antagonists. Additionally, using immunocytochemistry we detected colocalization of ER-α and the membrane-associated signaling protein caveolin-1. Importantly, using E(2)-conjugated bovine serum albumin (E(2)-BSA) and ER antagonists, we were able to show that the E(2)-mediated decrease in NPY secretion occurred through membrane-bound ER-α. Finally, using a combination of pharmacological inhibitors, we found that inhibition of the PI3K or AMPK pathway blocked the E(2)-mediated decrease in NPY secretion.

CONCLUSION

These findings indicate that the central anorexigenic action of E(2) occurs at least partially through hypothalamic NPY-synthesizing neurons. This regulation of NPY secretion occurs through rapid signaling mechanisms through membrane bound ER-α.

Simulating the influence of vernalization, photoperiod and optimum temperature on wheat developmental rates

BACKGROUND AND AIMS

Accurately representing development is essential for applying crop simulations to investigate the effects of climate, genotypes or crop management. Development in wheat (Triticum aestivum, T. durum) is primarily driven by temperature, but affected by vernalization and photoperiod, and is often simulated by reducing thermal-time accumulation using vernalization or photoperiod factors or limiting accumulation when a lower optimum temperature (T(optl)) is exceeded. In this study T(optl) and methods for representing effects of vernalization and photoperiod on anthesis were examined using a range of planting dates and genotypes.

METHODS

An examination was made of T(optl) values of 15, 20, 25 and 50 degrees C, and either the most limiting or the multiplicative value of the vernalization and photoperiod development rate factors for simulating anthesis. Field data were from replicated trials at Ludhiana, Punjab, India with July through to December planting dates and seven cultivars varying in vernalization response.

KEY RESULTS

Simulations of anthesis were similar for T(optl) values of 20, 25 and 50 degrees C, but a T(optl) of 15 degrees C resulted in a consistent bias towards predicting anthesis late for early planting dates. Results for T(optl) above 15 degrees C may have occurred because mean temperatures rarely exceeded 20 degrees C before anthesis for many planting dates. For cultivars having a strong vernalization response, anthesis was more accurately simulated when vernalization and photoperiod factors were multiplied rather than using the most limiting of the two factors.

CONCLUSIONS

Setting T(optl) to a high value (30 degrees C) and multiplying the vernalization and photoperiod factors resulted in accurately simulating anthesis for a wide range of planting dates and genotypes. However, for environments where average temperatures exceed 20 degrees C for much of the pre-anthesis period, a lower T(optl) (23 degrees C) might be appropriate. These results highlight the value of testing a model over a wide range of environments.

Anatomical study comparing the thickness of the volar and dorsal cortex of cadaveric adult distal radii using digital photography

INTRODUCTION

Dorsally displaced fractures of the distal radius fractures are one of the commonest in day-to-day practice. There is still no consensus among surgeons regarding the suitability of using volar or the dorsal cortex as basis for internal fixation for dorsally displaced fractures.

BACKGROUND

We report an anatomical study, which compares the thickness of the volar and dorsal cortices of cadaveric adult radii using digital photography.

RESULTS

Results of this study show that the volar cortex was statistically, significantly thicker than the dorsal cortex. We believe that the volar cortex may behave as the calcar of the distal radius and hence internal fixation devices applied to the volar cortex may provide a more stable internal fixation compared to those based on the dorsal cortex.

Patellar tendon ruptures in a pair of brothers

The patellar tendon does not easily rupture due to its considerable high tensile strength. Therefore, in normal individuals, ruptures of the patellar tendon are uncommon. We report three episodes of patellar tendon ruptures in two normally fit and healthy brothers; postulating the possibility of inherent weakness. The treatment options for these injuries are discussed.

Palmar cortical angle of the distal radius: a radiological study

Fifty lateral radiographs of normal wrists were viewed to determine the palmar cortical angle of the distal radius. The palmar cortical angle is different to its previously described palmar tilt or angulation. The mean value for the palmar cortical angle was 37 degrees (range, 26-50 degrees). This may be clinically important in the design of palmar plates for the distal radius.

Transitional cell carcinoma manifesting as acute cor pulmonale: cause of microscopic tumor embolism

Acute cor pulmonale is an uncommon manifestation of microscopic pulmonary tumor embolism. We describe the case of an 84-year-old man with a history of transitional cell carcinoma (TCC) of the urinary bladder who had acute cor pulmonale and died within a few hours after the onset of dyspnea. Autopsy showed that the right ventricle was dilated without hypertrophy. Microscopic examination of the lung showed that the small arteries, arterioles, and capillaries were filled with micrometastases of TCC. Microscopic pulmonary tumor embolism has rarely been reported with TCC, and to the best of our knowledge, such a fulminant course has not been previously described in the English language.

Lumbosacral plexopathy after dual kidney transplantation

A 58-year-old man underwent dual kidney transplantation. He was unable to move his right leg after surgery. This was caused by extensive lumbosacral plexopathy on the side of surgery. Lumbosacral plexopathy after kidney transplantation is uncommon, because the plexus has rich anastomotic blood supply, and ischemic injury is unlikely. However, isolated femoral neuropathy after renal transplantation has been reported, as the distal portion of this nerve is supplied by branches of internal iliac artery only and is more prone to ischemic injury during surgery. Dual-kidney transplantation involves a larger dissection, and the procedure takes 60 to 90 minutes longer than single-kidney transplantation. It involves more vascular reconstruction. This may predispose the lumbosacral plexus to ischemic injury. To the best of our knowledge, this is the first reported case of lumbosacral plexopathy after a dual kidney transplantation, and this may be seen more frequently because this procedure is becoming more common.

Pneumococcal bacteremia associated with an infected central venous catheter

Pneumococcus (Streptococcus pneumoniae) bacteremia is a serious infection. Pneumococcus has never been implicated as a cause of a central venous catheter-related bacteremia. It has been isolated from the catheter tip only twice before, and in one case caused the infection of an infusion port device. We report case of a 41-year-old woman who developed pneumococcal bacteremia after 6 days of an indwelling central venous catheter. The catheter tip grew > 300 cfu of S pneumoniae by the roll-plate method described by Maki and colleagues. No other focus of infection could be found in this patient. To the best of our knowledge, this is the first reported case of pneumococcal bacteremia associated with an infected central venous catheter.

Lady Windermere syndrome: middle lobe bronchiectasis and Mycobacterium avium complex infection due to voluntary cough suppression

An 81-year-old woman who presented with middle lobe bronchiectasis and Mycobacterium avium complex infection is described. She had a history of habitual suppression of cough, as in Lady Windermere syndrome. She was thin and had mild kyphoscoliosis but had no history of smoking or connective tissue disease. The middle lobe and lingula are predisposed to chronic inflammation because of their particular anatomic structures. Inability to clear the secretions from the airway due to voluntary cough suppression may predispose to bronchiectasis and M. avium complex infection.

Diffuse alveolar hemorrhage and pulmonary capillaritis due to propylthiouracil

Propylthiouracil (PTU) has recently been observed to be associated with antineutrophil cytoplasmic antibody (ANCA)-positive small vessel vasculitis, resulting in crescentic glomerulonephritis and, infrequently, diffuse alveolar hemorrhage (DAH). We describe a case of a 23-year-old pregnant woman who developed a perinuclear ANCA and antimyeloperoxidase-positive small vessel vasculitis manifesting as DAH and crescentic glomerulonephritis after she began taking PTU. An open lung biopsy was consistent with pulmonary capillaritis. She responded to corticosteroid therapy and discontinuation of PTU. DAH can be caused by pulmonary capillaritis, bland hemorrhage, or diffuse alveolar damage. To our knowledge, this represents the first documentation of an underlying pulmonary capillaritis in a case of PTU-induced DAH.

Functional suitability of commercially milled rice bran in India for use in different food products

The effect of blending of commercially available full fat and defatted rice brans in India from modern multistage rice mills with parboiling/stabilizing facilities in different food products in comparison to those obtained from laboratory milling of rice is reported. Bread volume and cookie spread decreased but muffin volume increased with the addition of different types of bran to wheat flour, however, the cookie spread factor was not affected by addition of full fat rice bran. The yields of the extrudate were increased by the blending of full fat rice bran but were decreased by the addition of defatted rice bran. Rice brans could be added to different food products to the extent of 5-10%. However, the full fat rice bran could not be used for production of extruded snack food.

A new approach to hysteroscopic cannulation of the fallopian tube

Hysteroscopic cannulation of the fallopian tube has become an essential part of the treatment of interstitial fallopian tube obstruction. This report describes the use of a flexible instrument that can be introduced through a rigid hysteroscope for the purpose of hysteroscopic tubal cannulation.

Genital tuberculosis: case report and literature review

A 64-year-old woman complained of abdominal pain and postmenopausal bleeding. A uterine curettage demonstrated acid fast bacilli and non caseating granulomas, indicating Mycobacterium tuberculosis. A chest roentgenogram revealed the presence of bilateral upper lobe calcific granulomas. The epidemiologic, diagnostic, and therapeutic implications of genital tuberculosis are discussed.

The effects of a few xenobiotics on certain phosphatases in the plasma of Clarias batrachus and Cirrhina mrigala

The effects of sublethal concentrations 1/2, 1/4 and 1/8 fractions of 96-h LC50 of aldrin and Swascofix CD-38 on alkaline, acid and glucose-6-phosphatases in the plasma of Clarias batrachus and Cirrhina mrigala were studied. These enzymes increased after exposure of fish to both xenobiotics. The increase was maximal after 20 days exposure to the highest concentrations. The enzyme increase was greatest in the fish exposed to aldrin.

DNA, RNA, protein and heterochromatin changes during embryo development and germination of soybean (Glycine max L.)

DNA, RNA, protein and heterochromatin were measured cytophotometrically in developing soybean (Glycine max) seeds. The average 2C DNA content for the soybean genome was 2.64 pg. The amounts of nuclear DNA in embryo axes showed no significant change during embryo development, whereas the DNA content in cotyledon nuclei increased significantly from 3.58 pg to 5.49 pg. The number of endopolyploid nuclei increased from 26% to 48% and the DNA content from 4.45 to 5.49 pg after cessation of cell division. The changes in RNA and protein content during embryo development were in general similar to those in DNA content. This can be interpreted that increased DNA levels in soybean cotyledons generated during embryogeny increase the protein synthesizing capacity. During the first 15 days of germination, the number of endopolyploid nuclei in cotyledons declined from 46% to 4%, and this decline is interpreted as DNA degradation providing a ready source of nucleosides and phosphates during early embryo growth. A later decline, however, between 15 and 20 days after germination, was age related similar to leaf senescence, because the percentage of endopolyploid nuclei remained unchanged while the number of non-viable cells increased. In senescing cotyledons, 73% and 80% of RNA and protein but only 20% of DNA were lost, as compared to dormant cotyledons. The heterochromatin (condensed chromatin) measurements indicated that nuclei of metabolically inactive dormant and senescent cotyledon nuclei contained an average of 33% more heterochromatin than nuclei from the green cotyledons of seedlings.

Reassociation Kinetics and Cytophotometric Characterization of Peanut (Arachis hypogaea L.) DNA

The base composition of peanut (var. NC-17) DNA determined from thermal denaturation profiles showed an average guanine plus cystosine content of 34% which was in close approximation to 36% guanine plus cytosine calculated from the buoyant density. Buoyant density also indicated the absence of satellite DNA. The genome size, 2.0 x 10(9) base pairs, as determined by reassociation kinetics of the single copy DNA was close to the genome size determined by cytophotometry, 2.1 x 10(9) base pairs. Peanut DNA averaging 450 to 600 base pairs long, reassociated in phosphate buffer and fractionated by hydroxylapatite, indicated a DNA genome composition of 36% nonrepetitive or single copy DNA; reassociation in formamide and followed by optical methods indicated the repetitive DNA possesses highly repeated, intermediately repeated and rarely repeated components of DNA with DNA sequences repeated on the average about 38,000, 6,700, and 200 times each. Different criteria of reassociation in formamide revealed further subdivisions of these four separate components of DNA. The DNA of above mentioned NC-17 variety compared to Florigiant variety showed no differences in thermal denaturation profiles, buoyant density, or in genome size.

Nonspecific light loss and intrinsic DNA variation problems associated with feulgen DNA cytophotometry

Nonspecific light loss by the cell-wall-plus-cytoplasm (CWC) can cause a 50% increase in Feulgen absorption units in peanut root-tip nuclei as determined by scanning at 450 nm, whereas this phenomenon is not evident with chicken erythrocytes. A two wavelength scanning method of subtracting nonspecific 450 nm absorption from 550 nm Feulgen absorption values eliminated the nonspecific light loss in CWC, However, the two wavelength scanning method is time consuming and somewhat impractical with a regular scanning microdensitometer such as Vickers M85. Elimination of the problem of nonspecific light loss is suggested by careful determination of background setting with the spot position close to the nucleus in CWC. The accuracy of the CWC background setting method was further tested by comparison with subtraction method. The use of plant nucleis as an internal standard in plant DNA measurements was also evaluated. Significant variation among the replicate slides due to the variation in pine nuclear DNA amounts was observed and plant nuclei generally are not reliable internal standards. Mature chicken erythrocytes are recommended as an internal standard because the cell type and metabolic state is known.

Feulgen cytophotometry of pine nuclei. II. Effect of pectinase used in cell separation

Pectinase used for cell separation prior to cytophotometry contains a DNase that is able to penetrate the cells of pine root tips and attack nuclear DNA. When pine root tips were exposed to 1% pectinase (pH 6.0), there was a decrease in nuclear DNA content at every sample point and a sharp drop between 16 and 20 hr. The effect of the DNase was eliminated by preparing the enzyme solution in 0.01 M sodium citrate or 0.001 M EDTA. It is suggested that heat denaturation of the DNase should also be effective and might be used in combination with the magnesium chelators.

Influence of Varied Phosphorus Supply on Growth and Xylem Sap Cytokinin Level of Sycamore (Platanus occidentalis L.) Seedlings

Effects of varying levels of phosphorus (P) on sycamore (Platanus occidentalis L.) growth and on the endogenous cytokinin levels in the xylem sap were tested. The seedlings were grown in aerated nutrient solutions in the greenhouse. Photoperiod was held constant at 16 hours. Four P concentrations, 0.02, 0.10, 0.50, and 2 mm, were used. There were no P deficiency symptoms even at the lowest P concentration. The maximum growth occurred in seedlings grown in 0.10 mm P. The greatest dry matter yield as well as stem height, stem diameter, and leaf area were produced at 0.10 or 0.50 mm P. The amount of cytokinin in xylem sap for each harvest during P nutrition followed closely the dry matter values, stem height, stem diameter, and leaf area.