Philip R. Cohen

The goal of this thesis is to model some of the cognitive structures and processes involve d in how people decide what to say in purposeful conversation. The main concern is to show how a speaker's knowledge of his/her hearer influences what s/he says. Utterances in such dialogues, where speakers can be presumed to be speaking for reasons, can best be viewed as the performance of "speech acts" (e.g., requesting). By modeling the process of deciding what to say as one of problem-solving, we show that the same mechanisms used to plan non-linguistic actions are applicable to planning of speech acts. The methodology of this research employs a computer program that integrates beliefs, goals, problem-solving, and reasoning, with the use of language. The program does this by planning speech acts when it determines that to achieve its situational goals, it needs to influence someone else's behavior. The system is able to plan request speech actrions to influence its user's goals, and inform speech acts to influence his/her beliefs. In addition, it is shown that speech acts can be used to achieve subgoals of other such acts. For instance, in addition to requesting that the user perform some action, the system can also decide to supply him/her with information necessary to performing that action -- information that it believes s/he does not already have. Our model is extendable to the more general problem of planning multiparty speech acts -- ones where actions requested by the speaker involve acts to be performed by parties other than the hearer. [MORE].

This paper explores principles governing the rational balance among an agent's beliefs, goals, actions, and intentions. Such principles provide specifications for artificial agents, and approximate a theory of human action (as philosophers use the term). By making explicit the conditions under which an agent can drop his goals, i.e., by specifying how the agent is committed to his goals, the formalism captures a number of important properties of intention. Specifically, the formalism provides analyses for Bratman's three characteristic functional roles played by intentions [7, 9], and shows how agents can avoid intending all the foreseen side-effects of what they actually intend. Finally, the analysis shows how intentions can be adopted relative to a background of relevant beliefs and other intentions or goals. By relativizing one agent's intentions in terms of beliefs about another agent's intentions (or beliefs'), we derive a preliminary account of interpersonal commitments

Background: Erythrasma is a benign dermatosis thattypically occurs on intertriginous skin. Purpose: Wedescribe a series of nine men with erythrasmathat were successfully treated with mupirocin 2%ointment monotherapy. Methods and Materials:We reviewed PubMed for the following terms:erythrasma, mupirocin, ointment, treatment. Wealso reviewed papers containing these terms andtheir references. Results: Complete resolution oferythrasma occurred following monotherapywith twice daily application of mupirocin 2%ointment. Conclusions: Several topical andoral treatments are available to successfullymanage erythrasma. Our series of patientswith erythrasma experienced resolution withmupirocin 2% ointment treatment within 2 to 4weeks of therapy. Monotherapy with mupirocin2% ointment should be considered as a primarytreatment alternative for erythrasma.

Hereditary hemochromatosis is an autosomalrecessive disorder that disturbs iron metabolismand results in iron deposition throughout the body.Iron accumulation in various organs may cause awide range of systemic symptoms and cutaneousmanifestations of the disease are particularlystriking. Classically, hereditary hemochromatosis hasbeen termed “bronze diabetes.” Although diffusehyperpigmentation is a well-described feature ofthis disease, other cutaneous symptoms may alsooccur, and a variety of anomalies may be observed.We present a case of long-standing hereditaryhemochromatosis associated with hypopigmentedplaques, which were found to be seborrheic keratoseson histologic examination. The cutaneous findingsin hereditary hemochromatosis are summarized andan unusual case of seborrheic keratosis manifestingas hypopigmented plaques in a man with hereditaryhemochromatosis is described. PubMed was usedto search the following terms: hemochromatosis,hereditary, hyperpigmentation, hypopigmentation,keratosis, melanin, seborrheic, siderosis. Despitethe generalized hyperpigmentation that is usuallyobserved in hereditary hemochromatosis, seborrheickeratosis may present rarely as hypopigmented lesionsin individuals affected by this disease. Therefore,seborrheic keratoses should be considered in thedifferential diagnosis in hemochromatosis patientswho present with uncharacteristic pigmentation.

Background: Bullous impetigo is a superficial skininfection caused by Staphylococcus aureus. Pyogenic granuloma is a common benigntumor frequently associated with prior trauma.Bullous impetigo and pyogenic granuloma may occurin pregnant women.Purpose: The features of a pregnant womanwith pyogenic granuloma and bullous impetigoconcurrently present in a lesion on her finger aredescribed.Methods: PubMed was used to search the followingterms: bullous impetigo, pregnancy, and pyogenicgranuloma. All papers were reviewed; relevantarticles, along with their references, were evaluatedResults: A red ulcerated nodule with a collaretteof epithelium around the tumor and surroundingbullae appeared on the fifth digit of the left hand of a31-year-old woman who was at 36 weeks gestation. Abacterial culture grew methicillin sensitive S. aureus.An excisional biopsy was performed. Histologicfindings revealed not only a benign vascular tumorwith an infiltrate of mixed inflammatory cells, butalso an intraepidermal blister. She received oralantibiotics and there was complete resolution of thefinger lesion and infection with preservation of digitfunction.Conclusion: Albeit uncommon, pyogenic granulomaand bullous impetigo may concurrently occur in thesame lesion. Therapeutic intervention should focuson treating both the benign skin tumor and theinfection.

Background: The sign of Leser-Trélat is characterizedby the sudden appearance of seborrheic keratosesassociated with an underlying malignancy. Objectives:An elderly man who developed multiple new-onsetseborrheic keratoses temporally associated witha diagnosis of mycosis fungoides is described andlymphoma-associated Leser-Trélat sign is reviewed.Methods: Pubmed was used to search the followingterms: cutaneous T-cell lymphoma, Leser-Trélat,leukemia, lymphoma, mycosis fungoides, and Sézarysyndrome. Papers with these terms and referencescited within these papers were reviewed. Results:An 84-year-old man developed multiple seborrheickeratoses temporally associated with a diagnosisof mycosis fungoides is presented. He was treatedwith bexarotene and achieved clinical remission;the number of seborrheic keratoses also decreased.Lymphoma-associated Leser-Trélat sign has beenobserved not only with mycosis fungoides but alsoother lymphomas and leukemias. Conclusions: Thesign of Leser-Trélat is predominantly associated withsolid organ adenocarcinomas. Albeit less common, aneruptive onset of seborrheic keratoses can also occurin association with hematopoietic malignancies.

BackgroundLocalized cutaneous argyria is a rare skin condition caused by direct contact with silver or silver particles. It presents as asymptomatic gray or blue-gray macules that appear similar to blue nevi. Histologic features include brown-colored or black-colored silver granules in the basement membrane and dermis, most commonly surrounding eccrine glands, elastic fibers, and collagen fibrils. The condition is most frequently observed in individuals who are regularly exposed to small silver particles, such as silversmiths and welders. However, localized cutaneous argyria has also been associated with acupuncture needles, silver earrings, and topical medications containing silver nitrate. Although the condition is benign, patients who are concerned about the cosmetic features of localized cutaneous argyria may benefit from laser therapy. PurposeWe describe the clinical and pathologic findings of two women who developed localized cutaneous argyria. We also review the characteristics of other patients with localized cutaneous argyria and summarize the differential diagnosis and treatment options for this condition. Materials and methodsThe features of two women with localized cutaneous argyria are presented. Using PubMed, the following terms were searched and relevant citations assessed: acquired localized argyria, acupuncture, argyria, argyrosis, colloidal silver, cutaneous argyria, and localized cutaneous argyria. In addition, the literature on localized cutaneous argyria is reviewed. ResultsTwo women presented with small, asymptomatic blue-gray macules appearing at sites directly adjacent to ear piercings. A punch biopsy was performed on one woman. Microscopic examination revealed a yellowish-brown colored granular material found adjacent to elastic fibers. Based on correlation of the clinical presentation and histopathologic findings, a diagnosis of localized cutaneous argyria was established. The second woman did not undergo a biopsy. However, the clinical presentation was highly suggestive of localized cutaneous argyria. Both women were reassured of the benign nature of the condition and agreed to return for clinical follow-up if they observed any changes in the appearance of the lesions.

The concept of joint action is at the core of numerous diverse research topics, including philosophical explorations of social action, studies of human dialogue, human-computer interaction, computer-supported collaborative work, multiagent systems, distributed artificial intelligence, distributed simulation, and contract law. It is therefore remarkable that so central a concept has received so little detailed analysis, in comparison with studies of individuals. However, in recent years, the study of joint action has begun to undergo more intense scrutiny, primarily from philosophers and researchers in artificial intelligence. These two disciplines often address similar topics but with different motivations, methodologies, tools, and criteria for success. Although this paper is inspired by philosophical work, it is squarely motivated by the concerns of building intelligent systems that are capable of collaborative behavior, either with a user, or with other such systems. Still, we hope that the paper sheds light on philosophical issues, and treats the subject of joint action at a sufficiently precise level to be illuminating of problems that any philosophical account needs to confront

This paper explores the truism that people think about what they say. It proposes that, to satisfy their own goals, people often plan their speech acts to affect their listeners' beliefs, goals, and emotional states. Such language use can be modelled by viewing speech acts as operators in a planning system, thus allowing both physical and speech acts to be integrated into plans. Methodological issues of how speech acts should be defined in a planbased theory are illustrated by defining operators for requesting and informing. Plans containing those operators are presented and comparisons are drawn with Searle's formulation. The operators are shown to be inadequate since they cannot be composed to form questions (requests to inform) and multiparty requests (requests to request). By refining the operator definitions and by identifying some of the side effects of requesting, compositional adequacy is achieved.The solution leads to a metatheoretical principle for modelling speech acts as planning operators

What is involved when a group of agents decide to do something together? Joint action by a team appears to involve more than just the union of simultaneous individual actions, even when those actions are coordinated. We would not say that there is any teamwork involved in ordinary automobile traffic, even though the drivers act simultaneously and are coordinated (one hopes) by the traffic signs and rules of the road. But when a group of drivers decide to do something together, such as driving somewhere as a convoy, it appears that the group acts more like a single agent with beliefs, goals, and intentions of its own, over and above the individual ones. [more]