What do we know about loyalty programs?

Loyalty and rewards program currently abound with every major hotel chain, airline, and car rental company having one. These programs are not just in the travel industry. Major supermarkets, restaurants, coffee shops and movie theaters also have them. Loyalty programs are not only ubiquitous, but some are very profitable. In 2022 Delta, United and American Airlines reported they earned a combined $8.4 billion from their loyalty program, which was greater than the three airlines combined operating income. This money primarily comes from co-branded credit cards that give users airline miles based on their spending. Data from Google’s Ngram program gives us the ability to see when people start using phrases. “Loyalty Program” and “Loyalty Rewards” were rarely used in English in the 1980, exploded in usage starting in the mid-1990s, and have not waned since. The falling cost of computers and data processing is making sophisticated rewards program available even to the smallest size companies.Accepted manuscrip

Effects of protein deficiency on testosterone levels, semen quality and testicular histology in the developing male rat

The aim of the study was to evaluate the effects of protein deficiency on plasma testosterone levels, epididymal sperm characteristics and testicular histology in the developing male rat. Twenty four Wistar albino rats were used in the study and were fed with a diet variously containing 3 %, 10 % and 20 % protein. Plasma testosterone levels were significantly lower in rats fed 3 % protein when compared to rats fed 10 % and 20 % protein (P<0.05). Testicular weight in protein deficient rats (rats fed 3 % and 10 % protein) was significantly lower than that of a control group (20 % protein) (P<0.05). No sperm was present in the epididymal duct lumen, but germ cells were observed in some duct lumens in rats fed 3 % protein. Epididymal weight decreased significantly in rats fed 3 % protein compared to rats fed 10 % and 20 % protein (P<0.05). The results of this study clearly show that protein deficiency in developing male rats adversely affects gonadal endocrine function, testicular histology and spermatogenesis

High-order delayed signal cancellation-based PLL under harmonically distorted grid voltages

Quasi type-1 phase-locked loop (QT1-PLL) has become very popular in recent times for grid-connected converters owing to its simple structure and fast dynamic response. By means of the use of a half-cycle moving average filter (MAF), this PLL can completely eliminate all the nominal frequency odd-order harmonics. However, the performance deteriorates when the grid experiences frequency drift. To address this issue, high-order non-adaptive MAF with the same window length has been proposed in the literature. Although it improves the off-nominal frequency performance, the filtering induced phase-lag remains the same. To address this issue, high-order delayed signal cancellation technique is considered in this study. The proposed technique demonstrates similar filtering performance as high-order MAF, however, by using lower window length. This makes the proposed technique fast responsive with lower memory requirement compared to similar other techniques in the literature. Detailed small signal modelling and associated parameter tuning method are established to facilitate the implementation of the proposed method inside current controllers of grid-connected converters. Comparative experimental results are provided with QT1-PLL and third-order QT1-PLL (TQT1-PLL) to illustrate the suitability and performance enhancement by the proposed method. These results show that in addition to the superior filtering capability of the proposed PLL, its settling-time is less than one cycle of nominal frequency under most grid conditions. Consequently, in terms of enhancing the dynamic response of the QT1-PLL, the proposed HDSC-PLL is superior to the TQT1-PLL

Apocrine adenocarcinoma of the nipple: a case report

Apocrine adenocarcinomas are rare malignant skin adnexal tumours. Apocrine carcinoma of the nipple is extremely rare and this case to the author's knowledge is only the third reported case worldwide and the first with associated ductal carcinoma in situ elsewhere in the breast. A seventy one year old caucasian female presented to the breast clinic with a growth on her nipple which proved on histopathological analysis to be an apocrine carcinoma. Recommended treatment for apocrine carcinoma includes surgery in the form of wide local excision

Are opinion leaders also opinion seekers? A research about technological products

Fikir liderliği kavramı çok sayıda çalışmanın konusu olmasına rağmen fikir arayanlarla ilgili çalışma sayısı azdır. Bazı ürün grupları için fikir liderlerinin aynı zamanda fikir arayan kişiler de olabileceğine yönelik araştırmalar mevcuttur. Ancak bu konudaki çalışmalar az olmakla birlikte bulguları açısından çelişkiler göstermektedir. Bu nedenle bu araştırmada fikir liderlerinin aynı zamanda fikir arayan olup olmadıkları teknolojik ürünler (bilgisayar, akıllı telefon, ev elektroniği ürünleri, vb.) üzerinden ölçümlenmeye çalışılmıştır. Araştırmada kişilerin kendilerini değerlendirecekleri anket formları kullanılmış ve toplamda geçerli 184 adet form üzerinden analizler yürütülmüştür. Araştırmanın bulgularına göre teknolojik ürünlerde fikir lideri ve fikir arayan kişilerin örtüşme durumu %19 olarak bulunmuştur. Ayrıca hem fikir liderliği hem de fikir arayışının yaş ve medeni duruma göre değişmediği ancak diğer demografik veriler açısından farklılık gösterebildiği tespit edilmiştir.Opinion leadership is the subject of many studies but the numbers of the studies about opinion seekers are less. In some product groups there are some available studies which suggest that opinion leaders are also opinion seekers. But these studies are unfortunately inedaquate and the findings are also controversial. Therefore, this research is aim that the proposal of opinion leaders also being opinion seekers is investigated through technological products (computer, smartphone, house electronics, etc.). In that context self-evaluation survey forms are used in the research and 184 valid forms are used in the analysis. According to the findings, for technological products, only 19% of the respondents are found to be both opinion leaders and opinion seekers in a relationship. In addition, it is found that opinion leadership and opinion seeking are not dependent on age and marital status; but there are differences according to other demographic variables

Use of a Global Positioning System (GPS) to Manage Extensive Sheep Farming and Pasture Land

The terrestrial climate is not sufficient to produce enough food to meet the roughage needs of the animals benefiting from the pasture lands because of excessive and early grazing of those areas. Plant growth is adversely affected in pastures that are not uniformly grazed. Tracking animals using the Global Positioning System (GPS) is a very important factor in determining the uniform distribution of grazing animals in a pasture, increasing the utilization rate of the pasture, and saving costs and time. With GPS tracking systems, establishing more effective pasture-use systems by monitoring the feeding regimes of small animals, the status of feed in the pasture, and the grazing behavior of the animals would be possible. The present study aimed to investigate the use of GPS for pasture and herd management in Turkey in addition to using the traditional techniques.In the present study conducted in the village of Köseyusuflu in Yozgat Province in May 2017, 2018, and 2019, grazing benefits that were determined from the pasture containing two Akkaraman sheep herds were recorded using GPS tracking devices. The results suggested that the area covered with vegetation along the sheep’s spring grazing routes varied between 43.6 and 62.9%, the ratio of legumes in the pasture grass in the low grazing areas was between 0.50 and 4.10%, and the grass species were between 12.75 and 44.50%. We determined that the sheep in herd A traveled between 7.6 and 9.9 km, while the sheep in herd B traveled between 4.7 and 5.7 km daily, and the two herds grazed an average of between 122 and 254 daa

Spatial variability of precipitation regimes over Turkey

Turkish annual precipitation regimes are analysed to provide large-scale perspective and redefine precipitation regions. Monthly total precipitation data are employed for 107 stations (1963–2002). Precipitation regime shape (seasonality) and magnitude (size) are classified using a novel multivariate methodology. Six shape and five magnitude classes are identified, which exhibit clear spatial structure. A composite (shape and magnitude) regime classification reveals dominant controls on spatial variability of precipitation. Intra-annual timing and magnitude of precipitation is highly variable due to seasonal shifts in Polar and Subtropical zones and physiographic factors. Nonetheless, the classification methodology is shown to be a powerful tool that identifies physically-interpretable precipitation regions: (1) coastal regimes for Marmara, coastal Aegean, Mediterranean and Black Sea; (2) transitional regimes in continental Aegean and Southeast Anatolia; and (3) inland regimes across central and Eastern Anatolia. This research has practical implications for understanding water resources, which are under ever growing pressure in Turkey

Top-Down Construction Cost Estimating Model using an Artificial Neural Network

This report contains the information and background on top-down cost estimating using artificial neural networks (ANN)_to enhance the accuracy of MDT early estimates of construction costs. Upon conducting an extensive review of MDT’s budgeting and cost estimating efforts, and following a survey of agency experts on the identification of the most salient project attributes with the dual-objectives of low effort and high accuracy, a rational method for top-down variable selection is proposed. Selected variables were further tested in their explanatory power of construction costs through the application of two cost estimating methodologies—multiple regression and artificial neural network methodologies. Both methods are shown to provide sizeable improvements over the agency’s current levels of prediction accuracy for its construction costs. Potential accuracy gains are also demonstrated to depend on project work types. The comparison of mean absolute percentage errors across different estimating methods confirms that the potential benefits from the proposed methodologies are expected to rise as the project level complexity and uncertainty increase. New construction and bridge replacement projects, for instance, are expected to gain the most in estimating accuracy since these two groups seem to exhibit considerably higher levels of deviation from the MDT’s preliminary cost estimates. To facilitate MDT’s implementation of the suggested methodology described in this report, a cost estimation methodology was also presented in an Excel spreadsheet format. This achieves two goals. First, it provides an accessible tool to make top-down cost predictions for agency planners during the budgeting stage based on MDT’s historical project data. Second, it furnishes a process through which the proposed model can be improved as new project information becomes available. Ultimately, the insights gained from this study are expected to contribute to a better formulation of the agency’s early cost estimation and budgeting efforts