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Background Open globe injury (OGI) is a serious condition that can lead to visual impairment and lifelong sequelae, brain activity of some brain regions would change in patients with OGI. Purpose To evaluate changes in brain activity associated with unilateral OGI by resting-state functional magnetic resonance imaging (rs-fMRI) and analysis of percentage amplitude of fluctuation (PerAF). Material and Methods A total of 22 patients with OGI (12 men, 10 women) and 22 healthy controls (HCs) matched for sex, age, and body weight were enrolled. All patients underwent rs-fMRI scans. Brain activity in the relevant brain regions was assessed with the PerAF method. The ability of PerAF to distinguish patients with OGI from HCs was assessed by receiver operating characteristic (ROC) curve analysis. We also examined the relationship between Hospital Anxiety and Depression Scale (HADS) scores and PerAF signals by Pearson’s correlation analysis. Results PerAF values in amygdala_R and Frontal_Inf_Orb_L/Frontal_Inf_Oper_L were increased whereas that in Cerebellum Anterior Lobe/Cerebelum_8_L was decreased in patients with OGI compared to HCs. The areas under the ROC curve showed that these brain regions could distinguish between patients with OGI and HCs. The PerAF value of amygdala_R was positively correlated with HADS scores. Conclusion Changes in PerAF in the amygdala_R, Frontal_inferior_Orb_L/Frontal_Inf_Oper_L, and Cerebellum Anterior Lobe/Cerebelum_8_L in patients with OGI may be related to an increased risk of developing psychiatric disorders such as anxiety and depression. PerAF can be used to investigate the neural basis of complications associated with OGI and monitor disease progression.

Background and Purpose: Research suggests that women and men may present with different transient ischemic attack (TIA) and stroke symptoms. We aimed to explore symptoms and features associated with a definite TIA/stroke diagnosis and whether those associations differed by sex. Methods: We completed a retrospective cohort study of patients referred to The Ottawa Hospital Stroke Prevention Clinic in 2015. Exploratory multinomial logistic regression was used to evaluate candidate variables associated with diagnosis and patient sex. Backwards elimination of the interaction terms with a significance level for staying in the model of 0.25 was used to arrive at a more parsimonious model. Results: Based on 1770 complete patient records, sex-specific differences were noted in TIA/stroke diagnosis based on features such as duration of event, suddenness of symptom onset, unilateral sensory loss, and pain. Conclusions: This preliminary work identified sex-specific differences in the final diagnosis of TIA/stroke based on common presenting symptoms/features. More research is needed to understand if there are biases or sex-based differences in TIA/stroke manifestations and diagnosis.

Background and Purpose: The diagnosis of transient ischemic attack (TIA) is largely dependent on a process of clinical decision-making that remains poorly characterized in the absence of a validated and accessible biomarker or imaging test. We performed a retrospective chart review to identify variables associated with a final neurologist diagnosis of TIA/stroke. Methods: Records for all patients seen in The Ottawa Hospital’s Stroke Prevention Clinic in 2015 were analyzed for patient and referral characteristics, features of the presenting neurological event, and final diagnosis by a stroke neurologist (classified as definite, possible, or definite not TIA/stroke). Multinomial logistic regression analysis with backward elimination was used to identify variables associated with the final diagnosis. Results: Our inclusion criteria were met by 1894 patients. After backward elimination, 23 potentially important variables were identified, including monocular vision loss (odds ratio [OR]: 30.4, 95% confidence interval [CI]: 14.6-63.3), symptoms of sudden onset (OR: 28.3, 95% CI: 14.2-56.2), unilateral weakness affecting 2 or 3 of face, arm, or leg (OR: 17.7, 95% CI: 9.8-31.7), and homonymous hemianopia (OR: 16.6, 95% CI: 8.1-34.0). Conclusions: Accurate diagnosis of TIA is essential to initiating appropriate secondary stroke prevention therapies. A focus on elements of the patient history most commonly associated with a final diagnosis of TIA/stroke may help to identify patients in greatest need of urgent SPC assessment and allow for the provision of effective and efficient stroke prevention services.

Background: Nipple discharge cytology is a simple non-invasive method that may provide valuable information for detecting underlying malignancy. Several studies have investigated the diagnostic value of cytology in breast cancer patients with pathological nipple discharge, but the results have been highly variable. Herein we presented a systematic review and meta-analysis of published studies pertaining to the diagnostic capacity of nipple discharge cytology in patients with breast cancer. Methods: A systematic literature search was performed (Medline/PubMed, Embase, Cochrane Library databases, and Google Scholar) to identify studies that investigated the diagnostic capacity of cytology with regard to breast cancer in patients with pathologic nipple discharge. Two independent researchers identified articles that assessed the sensitivity and specificity of cytological evaluation for breast cancer detection in patients with pathologic nipple discharge published between January 2000 and October 2018. Articles were only included in the meta-analysis if they met predetermined criteria. The characteristics of each study and the data they yielded were summarized. Quality assessment of all articles included was performed using the Methodological Index for Non-randomized Studies Criteria (MINORS) and the Quality Assessment of Diagnostic Accuracy Study 2 (QUADAS-2). Heterogeneity was tested via Cochran Q test and the I2 statistic using Stata 12.0 and Meta-DiSc 1.4 software, and meta-analysis was performed. Results: A total of 286 articles were identified, of which 12 articles including a total of 1476 patients were deemed eligible for inclusion in the meta-analysis. A random-effects model assessing the capacity of nipple discharge cytology to predict breast cancer yielded pooled sensitivity 63% (95% confidence interval [CI]: 53%-72%), specificity 95% (95% CI: 87%-98%), positive likelihood ratio 12.35 (95% CI: 4.87-31.34), and negative likelihood ratio 0.39 (95% CI: 0.30-0.50). The diagnostic odds ratio was 31.88 (95% CI: 11.30-89.98). The area under the summary receiver operating characteristic curve was 0.79 (95% CI: 0.75-0.82). Conclusion: The current meta-analysis suggests that nipple discharge cytology is a useful diagnostic modality for detection of breast cancer in patients with pathological nipple discharge, with moderate sensitivity and high specificity. Key words: Breast carcinoma; Cytology; Diagnosis; Meta-analysis; Nipple discharge

With developments of deep learning technologies and increasing demands for industrial process feature extractions, researchers pay much attention to deep learning of process historical data. Curren...

Correlation analysis has been widely applied for process detection and alarm analysis. However, traditional correlation analysis methods have been found inefficient due to the influence of process time delays on analysis results. In this paper, we propose an alarm correlation analysis method based on block matching similarities. By converting alarm data sequences to time node sequences, the block matching similarity (BMS) method is able to reduce the calculation burden of the correlation analysis. Considering time delays between the alarm variables, the improved maximal correlation coefficient method is presented to reduce the effect of time delays and to improve the accuracy of the correlation analysis. A numerical case and the Tennessee Eastman process are employed to demonstrate the effectiveness and efficiency of the proposed method.

Background and Purpose— The ESCAPE trial (The Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times) was a multicentre, randomized controlled trial of endovascular thrombectomy versus standard care for patients with acute ischemic stroke that allowed patients to be enrolled with deferred consent. We investigated the knowledge and opinions of these patients or their authorized third parties about the consent process. Methods— All patients (or their authorized third parties) enrolled with deferral of consent in ESCAPE were invited to complete a 12-question survey within the first 4 days of enrollment and again at 90 days. Questions investigated knowledge of the ESCAPE trial and opinions on deferral of consent. Results— Of 56 patients enrolled with deferred consent, 33 (59%) completed the initial survey, and of these, 27 (81%) completed the 90-day follow-up. Enrollment with deferred consent was not associated with a significant difference in door-to-randomization times (50.5 versus 57 minutes; P =0.29) but allowed these 56 patients to participate in the trial. Only 52% of respondents understood that patients could be randomized to thrombectomy or standard care, although most understood the other basic principles of the trial. At baseline and at 90 days, respondents disagreed or strongly disagreed with deferred consent in acute stroke trials generally (82% and 78%) and in the ESCAPE trial specifically (93% and 91%). Conclusions— Respondents generally disagreed with the use of deferred consent for enrollment in the ESCAPE trial and in stroke trials more generally.

The Belt and Road Initiative (BRI), a global development plan proposed by Chinese President Xi Jinping in 2013, has attracted widespread attention in China and abroad since it was first proposed. To explore attitudes of the U.S. press towards the initiative and views of China illustrated in these media, the present work adopts Karin Fierke’s “Language Game” Constructivism to study news reports on the BRI collected from The New York Times. Qualitative and quantitative approaches are combined to illustrate language strategies used by the media with the help of corpus software. The study shows that derogatory terms and five language game strategies have been used to report on the initiative to discredit China’s image and the initiative from different angles. Overall negative and suspicious attitudes illustrated by the press can be identified. The analysis shows that strategies adopted by the American side for slander are based on differences in collective memories and knowledge shared by China and the United States. The cultural gap between these two nations has created different national ideological models, which has led to varied identities and interests in the international system. The present research is intended to enrich the application of “language game” constructivism to news discourse by combining “language games” with image construction. More importantly, the author expects the results of this study to help the Chinese side respond to future policy misunderstandings.

Objective Neuroimaging studies have shown that patients with pain-related conditions have altered neuronal activity and structural functions. The purpose of this study was to investigate whether patients with classical trigeminal neuralgia (CTN) exhibit changes in corresponding neuronal activity via analysis of neuronal activity regional homogeneity (ReHo). Methods A total of 28 patients presenting with sore eyes (12 men and 16 women) were matched with 28 healthy controls (12 men and 16 women). All participants underwent functional magnetic resonance imaging (fMRI). This ReHo method was used to assess the consistency of changes in neural activity in various brain regions. The receiver operating characteristic (ROC) curve was applied to differentiate ReHo values of patients with CTN from ReHo values of healthy controls. Pearson's correlation analysis was applied to evaluate the correlation between ReHo values of different brain regions of patients with CTN and clinical manifestations. Results Compared with healthy controls, patients with CTN were found to have increased ReHo values in the inferior cerebellum bilaterally, right inferior temporal gyrus, right middle occipital gyrus, right fusiform gyrus, right superior frontal gyrus, and right precentral gyrus. ROC curve analysis of each brain region revealed near-perfect accuracy regarding the area under the curve. However, no correlation between ReHo values and clinical manifestations in patients with CTN was found. Conclusions CTN is associated with altered neuronal networks in different areas of the brain. ReHo values all possess different degrees of change, implying that CTN has a certain impact on cerebral function.

AIM: To explore the intrinsic brain activity variations in retinal vein occlusion (RVO) subjects by using the voxel-wise degree centrality (DC) technique. METHODS: Twenty-one subjects with RVO and twenty-one healthy controls (HCs) were enlisted and underwent the resting-state functional magnetic resonance imaging (rs-fMRI) examination. The spontaneous cerebrum activity variations were inspected using the DC technology. The receiver operating characteristic (ROC) curve was implemented to distinguish the DC values of RVOs from HCs. The relationships between DC signal of definite regions of interest and the clinical characteristics in RVO group were evaluated by Pearson’s correlation analysis. RESULTS: RVOs showed notably higher DC signals in right superior parietal lobule, middle frontal gyrus and left precuneus, but decreased DC signals in left middle temporal gyrus and bilateral anterior cingulated (BAC) when comparing with HCs. The mean DC value of RVOs in the BAC were negatively correlated with the anxiety and depression scale. CONCLUSION: RVO is associated aberrant intrinsic brain activity patterns in several brain areas including pain-related as well as visual-related regions, which might assist to reveal the latent neural mechanisms.

Energy efficiency prediction models promote the efficient uses of energy and low consumptions of raw materials. The Convolutional neural network (CNN) is one of the most effective deep learning networks for complex process modeling. However, when applied to real industrial processes, the performance of the CNN would be restricted by the change of operating conditions, such as swings in feedstock qualities, different manufacturing strategies and variations in product specifications. A globally invariant model is unable to adapt the time-varying conditions. Therefore, we proposed a multiple operation modes adaptive time window convolutional neural network (MOM-ATWCNN). Here, a hierarchical clustering approach is suggested to determine the numbers and locations of the modes. Then, an optimal length of time window is selected to match with each mode accordingly. Lastly, the improved deep learning model is used to extract the varying features hidden in different modes. To verify the effectiveness, the proposed method is compared to several typical deep learning models by the data collected from a real industrial atmospheric and vacuum distillation process. The results show that the energy prediction accuracy of the MOM-ATWCNN is 6.5%, 2.9% and 10.2% higher than those of the traditional CNN, LSTM, BPNN, respectively. Furthermore, the proposed method exhibit its superiority regarding various performance indexes. The improvement of the algorithm is beneficial to the reduction of energy consumptions thus achieving economic goals.

An image-matching assisted dual-frequency phase-sensitive optical time domain reflectometry ( Φ − O T D R ) is proposed and demonstrated. Compared to the conventional dual-frequency Φ − O T D R , which retrieves data via curve matching, the proposed scheme can effectively improve the temporal resolution and measurement precision while keeping the spatial resolution without additional hardware. In the experiments, with a 10 s temporal window, the proposed scheme realized the same measurement precision as the conventional method that used a 40 s window, suggesting a fourfold improvement of temporal resolution. When both used the 10 s temporal window, the measurement error was suppressed from 21.4% to 1.2% in the sensing for a 2 m hot zone at the end of a 90-m fiber.

Objective To investigate the potential regional homogeneity (ReHo) brain activity changes in patients with corneal ulcer (CU) and their possible relationship with clinical symptoms. Materials and Methods Forty patients with CU (26 men and 14 women), and 40 healthy controls (HCs) (26 men and 14 women) closely matched in age, sex, and weight underwent resting-state functional MRI scans, respectively. The ReHo method was applied to evaluate synchronous neural activity changes. Receiver operating characteristic curve (ROC curve) was used to show high test-retest stability and high degree of sensitivity and specificity. We utilized the correlation analysis to calculate the relationship between the average ReHo signal values in different brain areas and the clinical symptoms in CU patients. Results Compared with the HCs, CU patients had significantly increased ReHo values in right cerebellum posterior lobe, left cerebellum posterior lobe, left inferior temporal gyrus, right lingual gyrus, left middle frontal gyrus, left angular gyrus, left cingulate gyrus, right angular gyrus and bilateral superior frontal gyrus, and decreased ReHo values in right anterior cingulate and left precentral gyrus. ROC curve analysis of each brain regions showed the accuracy of AUC was perfect except the right cerebellum posterior lobe. Nevertheless, there was no clear evidence of prominent relevance between the average ReHo values in brain areas and the clinical symptoms. Conclusion Corneal ulcer caused dysfunctional adaption in different brain areas, which including relatively increased values and decreased values. This finding may help us take a further step in exploring the underlying pathologic mechanisms of CU.

Effective management of Transient Ischemic Attack (TIA) and stroke hinges on accurate diagnosis. Research suggests that women and men present with different TIA/stroke symptoms, and those more commonly reported by women are often considered atypical, or benign. For this reason, TIA or stroke in women may be underdiagnosed and undertreated. Growing evidence that women are disproportionately affected by stroke underpins this study focused on neurologist diagnosis of stroke/TIA in association with presenting symptoms. A retrospective chart review was performed using data from the charts of all patients referred to The Ottawa Hospital Stroke Prevention Clinic in 2015 with a provisional diagnosis of TIA/stroke. Demographics, event characteristics, and final diagnosis were extracted from each chart. Multinomial logistic regression analysis with backwards elimination and a significance level staying in the model of α=0.15 was used to identify variables associated with a final diagnosis of definite TIA/stroke. A sub-analysis was completed for the final model by sex. Of the 1864 included patients, 932 (50%) were women. There were no significant differences in age or final diagnosis of definite TIA/stroke based on sex. Among patients reporting classic stroke symptoms such as unilateral weakness, aphasia, and amaurosis fugax both sexes demonstrated significantly higher odds of a final diagnosis of TIA/stroke; however the odds were higher for men than women. For example, men with unilateral weakness, aphasia or amaurosis fugax had an odds ratio (OR) of 32.7, 7.7, and 27.8 respectively of having a final diagnosis of TIA/stroke, whereas the OR for women was 10.9, 5.4, and 22.2 respectively, although the 95% confidence intervals overlapped. In contrast, women reporting homonymous hemianopsia or any combination of ataxia, diplopia, or vertigo had a higher odds than men of being diagnosed with TIA/stroke (OR 21 and 8.5 respectively for women and OR 11.4 and 5.1 respectively for men). The trend in differences noted for the odds of definite TIA/stroke diagnosis among men and women may imply that women are less likely to be diagnosed with TIA even when reporting classical symptoms. More research is needed to understand sex-based differences in the diagnosis of TIA/stroke.

We propose a duplexer based on spoof surface plasmon polaritons (SSPPs) transmission lines (TLs). The duplexer consists of two domino SSPP TLs with different lower cut-off and higher cut-off (asymptotic) frequencies, forming the two frequency band channels. The low frequency band channel is the domino SSPP TL with higher unit height. For the branch of the high frequency band channel, which is based on a SSPP TL with lower unit height, multiple SSPP TL sections functioning as band-stop structures are placed aside the SSPP TL to realize satisfying out-of-band rejection below the lower cut-off frequency. The two branches are fed through a common rectangular waveguide. Different transition length of the two branches as well as a shifted placement from the center is designed to achieve efficient transition for both branches at respective bands.

Recent studies have reported structural and functional abnormalities in multiple brain regions of classical trigeminal neuralgia (CTN) patients. Differences in spontaneous neuronal activity between CTN patients and healthy subjects, however, remain unknown. The aim of the present study was to investigate alterations in brain activity by application of amplitude of low frequency fluctuation (ALFF), thus analyzing the correlation between durations of spontaneous pain intensity and ALFF values in CTN patients. A total of 28 CTN patients (male, n=12; female, n=16) and 28 healthy controls (HCs; male, n=12; female, n=16) matched for age and sex were enrolled. All subjects underwent resting‑state functional magnetic resonance imaging and changes in spontaneous brain activity were investigated using an ALFF method. Receiver operating characteristic (ROC) curve analysis was applied to differentiate ALFF values of CTN patients from HCs. Altered ALFF values and clinical manifestations were evaluated using Pearson's correlation analysis. ALFF values of the bilateral inferior cerebellum, bilateral fusiform gyrus, right precentral gyrus, left inferior temporal gyrus, right superior cerebellum, left inferior occipital gyrus and right superior occipital gyrus were significantly higher in CTN patients when compared to HCs. ROC curve analysis of each brain revealed a near‑perfect AUC accuracy. Pearson's correlation analysis revealed the visual analog scale of the right eye to be positively correlated with both left inferior temporal and occipital gyral findings, while episode duration likewise was positively associated with left inferior temporal gyral findings. CTN patients exhibited abnormal spontaneous activity in multiple brain regions closely related to pain regulation and perception, while VAS and CTN episode duration were positively correlated with ALFF signal values in some brain regions. The present findings provide further insight into the pathological mechanisms underlying CTN.

Objective: Crosstalk between the brain and immune system has been implicated in the dev elo pm e nt ofmental disorders. The hypothalamic pituitary adrenal axis serves as an important bridge forthis process. This study aims to investigate the relationship between the fluctuation of plasmaglucocorticoid (GC) and microglial activation in the ventral hippocampus during social defeat. Methods: Intruder—residen t paradigm was used to establish the rodent model of acute social de feat.The plasma GC of intruder mice was obtained serially after social aggression. Simultaneously,social behaviors in the novel context, microglial activation, and inflammation in the ventralhippocampus were tested. Results: Results showed that plasma GC is high during 0.5-8 hours after social aggress io n and thenrecovered. Behavior test showed that social fear and avoidance in the novel context isobserved at day 3 after stimulation, and then social interaction increased at day 7 afterstimulation. High expression of glucocorticoid receptor (GR), NLRP3, and IL-18 accompaniedmicroglial activation in the ventral hippocampus at day 3, and then diminished at day 7 after stimulation. Ventral hippocampal inflammation is correlated with the changes in socialbe havior. Additionally, muscimol, a GABA agonist, was bilaterally microinjected to basolateralamygdala, which alleviated the social avoidance and ventral hippocampal inflammation. Conclusion:Our results suggested that acu te social defeat that leads to ventral hippocampal microglialactivation and inflammatory cytokine release depend on the activity of basolateral amygdala,but not the fluctuation of the plasma GC.

Many lighting energy-saving modification programs have the embarrassment of uneconomical. Th is paper takes into account economic evaluation to solve the problem. According to illu minative equip ments price, life span and power consumption, the optimal program will be found under the limited investment. Firstly, the benefit ratio will be used to evaluate on the equipments modification necessity, and get the modification sequence. If the b iggest benefit ratio is in different equip ment simu ltaneously, the better one will be selected in terms of relat ive investment recovery period. The relat ive remaining t ime is innovatively introduced into economic evaluation for determining the equip ments modification locations. Then the system operation flowchart is to prove that the scheme is workable.

We propose a frequency splitter based on spoof surface plasmon polariton (SSPP) transmission lines (TLs). The device consists of two bent domino SSPP TLs with different geometric parameters, leading to different passbands, forming two frequency band branches. A transition from a rectangular waveguide to the two SSPP TLs is designed for frequency splitting. To achieve efficient transition for both branches in their respective frequency bands, different transition lengths of the two branches and a shifted placement from the center are adopted. Furthermore, for the high frequency band branch, to obtain satisfactory out-of-band rejection below the lower cut-off frequency, an SSPP bandstop structure is introduced by placing SSPP TL sections along the main SSPP TL. A prototype is designed, fabricated, and evaluated. The results prove the feasibility of the proposed SSPP frequency splitter.

Fei Qin,1,* Yun Ma,1,* Xiao Li,2 Xian Wang,1 Yuanyi Wei,1 Chuqi Hou,3 Si Lin,1 Lianbing Hou,1 Chengxi Wang4 1Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou, 2Department of Pharmacy, the Affiliated Hospital of Qingdao University, Qingdao, Shandong, 3Department of Pharmacology, Southern Medical University, 4Department of Pharmacology, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Up to 90% of patients develop adhesion following laparotomy. Upregulating fibrinolysis within the peritoneum reduces adhesions. Tanshinone IIA (Tan IIA) promotes fibrinolysis in hepatic fibrosis and the cardiovascular system and may play a role in preventing adhesions. We report preparation and characterization of liquid nanoparticles of Tan IIA for intravenous administration and investigate its feasibility in clinical practice. Tan IIA liquid nanoparticles (Tan IIA-NPs) were prepared using the emulsion/solvent evaporation method. Adhesions were induced in Sprague–Dawley rats by injuring the parietal peritoneum and cecum, followed by intravenous administration of various Tan IIA-NP dosages. The adhesion scores for each group were collected 7 days after the initial laparotomy. The activity of tissue-type plasminogen activator (tPA) was measured from the peritoneal lavage fluid. The messenger RNA and protein expression levels of plasminogen activator inhibitor-1 (PAI-1) were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. TGF-β1 and collagen I expressions were measured immunohistochemically in the ischemic tissues. The effects of Tan IIA-NPs and free-Tan IIA on tPA and PAI-1 were measured in vitro in TGF-β1-induced HMrSV5 cells. Tan IIA-NPs exhibited small particle size, high encapsulation efficiency, good stability for storage, and safety for intravenous administration. Tan IIA-NPs were effective in preventing adhesion. Tan IIA-NPs increased tPA activity in peritoneal lavage fluid, and tPA mRNA and protein expression, and decreased PAI-1 mRNA and protein expression in the ischemic tissues. Moreover, Tan IIA-NPs decreased TGF-β1 and collagen I expressions in the ischemic tissues. Tan IIA-NPs administered via tail veins upregulated fibrinolysis in the peritoneum. Invitro studies showed that these effects may be mediated by the TGF-β signal pathway. Keywords: peritoneal fibrinolysis, tissue-type plasminogen activator, plasminogen activator inhibitor-1

Test power consumption is becoming a major concern in low power integrated circuits(ICs). This paper presents a revised low power compression architecture for scan test. In this paper, the variance in power consumption is used to select test pattern during scan test, and a low power feedback MUX is added to the scan chains. Simulation results by mathematical methods show that the proposed test architecture is promising in reduction of power consumption.

Course deviation of vehicle during running will bring about traffic accidents, and many factors such as the assembling and processing quality of suspension system and steering system will lead to vehicle course angle deviation. For an in-depth study of vehicle course angle deviation, an online automatic detecting method was worked out, which can control a CCD camera to grab images by a photoelectric switch and apply image processing technique to extract key points to calculate the amount of course angle deviation.

We report on the design and construction of a l–3μ infrared photometer. We use a pre-focus rotating chopper to effect modulation and, unlike some previous designs, we use the chopper to feed in the sky background only, and use a fixed mirror to feed in the star signal. In this way, excess demand on the precision setting of the rotating chopper Is avoided. Test observations on a 1-m telescope show that our photometer is capable of observing all the IRC sources with an accuracy better than O.lmag at a time constant of 2 minutes.